A Killer F5 Tornado Rips Through Dallas County -- How Ready Are We for this Nightmare Scenario?
Tim Marshall and his wife, Kay, were bickering like seagulls when the cow dung flew inside their pickup's passenger-side window and splattered across his face. "Put the vehicle in drive," Marshall said in a hectoring tone that any spouse would find annoying. "No. No. No. We are fine. We...are...fine."
About a half-mile away, a wedge-shaped tornado was heading straight at them, cutting across a field peppered with some low-slung farm and industrial buildings that were about to be blasted into oblivion. To Marshall, who's been keen on weather since his boyhood, this was no time to flee, even if the chunky black twister, a rare and violent F5, was bearing down on him and his wife, whom he recruited "as sort of a last resort" to be his storm-chasing driver.
In the video footage the Irving engineer captured from that spot—an overpass on Interstate 44 just north of Newcastle, Oklahoma—the tornado hangs perilously from a shroud of black clouds, rotating and churning in debris-laden shades of black and gray.
As it rips through electrical transformers, the flashes and explosions can be seen getting sucked back into the vortex. Dirt and tree limbs wake out from the bottom of the funnel, hinting at its destructive power, while at a bit more distance from the cylinder an intense wind known as the rear flank downdraft is hurling lighter objects across the sky, including the shower of cow dung that found Marshall's face.
"It's actually shaking the ground, like in Jurassic Park," Marshall explains later, referring to the rings in the puddle signaling T. rex's arrival in the movie. As far as tornadoes go, this one also tops the food chain, and it has burned the date May 3, 1999, into the memories of many Oklahomans.
The twister, one of the best-recorded in history, was on the ground for 37 miles, nearly all of it in open country, but in its track lay the tiny farm town of Bridge Creek and three Oklahoma City suburbs. Along that path, it killed 36 people, injured 295 and turned whole neighborhoods to rubble. In all it destroyed 1,780 homes and did $963 million in property damage, making it the costliest tornado on record. Its winds were clocked at 301 mph, the highest wind speed ever recorded by a mobile Doppler radar (with a margin of error of 20 mph). In Bridge Creek, where it grew a beastly mile wide, it tossed about a dozen cars a quarter-mile. A canceled check from an aircraft parts business near its starting point turned up 65 miles away, on the other side of Oklahoma City. It had just a minor tear in one corner.
Statistically, Dallas-Fort Worth is only slightly less vulnerable than central Oklahoma to a violent tornado, an EF4 or EF5, and federal weather researchers have said repeatedly the region is an overdue target for a major strike. (The Enhanced Fujita scale, like the F-scale damage-intensity measurements it replaced in 2007, infers wind speeds from damage to buildings, trees and other objects. EF4 winds begin at 166 mph and are capable of leveling well-constructed houses. While about 2 percent of all tornadoes are rated EF4 or EF5, they account for 65 percent of tornado deaths.) Dallas is well within the southern Great Plains' "Tornado Alley," an area with a distinct tornado season from April through June. Conditions are right this time of year for dry air from the north and west to clash with warm, moist air from the Gulf of Mexico, setting up the unstable conditions that lead to the formation of supercell thunderstorms that spawn twisters.
Yet Dallas' vulnerability has inspired less than full preparation by disaster response officials and prompted few homeowners or builders to construct storm shelters above or below ground.
"A level-5 tornado hitting inside the city limits is too big to plan for," says city of Dallas emergency management director Kenny Shaw. "It would be a mass casualty event requiring outside resources on a large scale. We are not sitting around trying to figure out what to do in these worst-case scenarios. We'd have a response, we have response planning, but it would not run smoothly by any means."
One of the city's chief partners in emergency response, the Dallas Area Chapter of the American Red Cross, committed itself this winter to provide mass care in the event of just such a tornado strike. The nonprofit agency aims to build the capacity to provide food and emergency housing to 40,000 people, the number it estimates would be left without homes in the event of a major tornado. The $50 million project, dubbed "Protect the Metroplex," uses the 1999 Moore, Oklahoma, tornado as its model threat. Steve Vetrano, the organization's chief operating officer, says the Red Cross hopes to complete the project by September 2011, the chapter's 100th anniversary. To do so, it needs to train 11,000 more volunteers than the 3,000 it currently has on its roster, acquire 37,500 cots above the 2,500 now in its warehouses, and conduct a massive planning effort to identify schools, churches and other buildings that could serve as temporary shelters.
"Before Hurricane Katrina, we always thought help would be on the way, but it was not," says Cheryl Sutterfield-Jones, the Dallas chapter's chief executive officer. "I don't want to look at you and say, 'We didn't get that response.' We should be able to take care of our own if this disaster happens tomorrow."
As it gears up its fund-raising and spreads the work out among other local agencies such as the North Texas Food Bank, the Salvation Army and the Volunteer Center, the nonprofit is putting together a "what if" video, using Marshall's storm footage to dramatize its point. It likely won't include the running husband-wife commentary, like Kay's remark after they fled the overpass with no time to spare: "Do that again, and I'll divorce your ass."
With one local institution planning for the prospect of an EF5 tornado hitting the region's most densely populated areas, the Dallas Observer looked around to find others in the city who are thinking about the unthinkable. What are the probabilities of it happening? What would it look like? What are some of the area's vulnerabilities should the big one blow into town?
It's a subject that gets little attention, says Martin Lisius, a veteran storm chaser from Arlington and chairman of the Texas Severe Storms Association, a nonprofit dedicated to severe weather education. "When it happens, and it will in our lifetime, people will be completely stunned."
My house in East Dallas stands to be hit by a twister rated EF4 or greater only once every 5,000 years, according to Harold Brooks, a federal research meteorologist who has analyzed tornado data going back to 1921 and arrived at the "return rate" of tornadoes for points around the country. Those odds hardly inspire me to get to work digging a concrete-reinforced hidey-hole in the backyard.
But extend the threat out to an EF4 or better hitting within 25 miles of my house—or 25 miles from downtown Dallas for that matter—and the "return rate" shrinks to about 33 years, or three times per century, says Brooks, who works at the National Severe Storms Laboratory in Norman, Oklahoma.
Hence his conclusion: Dallas is "overdue." Since 1950, only one 4-rated twister has touched down in either Dallas, Tarrant, Denton or Collin counties: the April 25, 1994, Lancaster tornado that struck just after 9:30 at night and killed three people along a six-mile path of destruction that included the suburb's historic downtown square. In the past 59 years, only one other tornado has caused fatalities in Dallas County. On April 2, 1957, an Oak Cliff tornado killed 10 and injured 200 after it touched down just east of what is now Executive Airport and moved almost straight north into West Dallas and the Love Field area. Appearing in the late afternoon in relatively bright light, the F3-rated twister was heavily documented by TV and still photographers who captured it transforming from a rope-like wisp to a relatively stout funnel about 100 yards wide. At one point along its 17-mile path, it formed multiple funnels before dissipating around Bachman Lake. The tornado that ambled into downtown Fort Worth on March 28, 2000, was classified as a weak F3, but was likely losing intensity when it began hurling roof gravel downtown and damaging 17 high-rise buildings. Two people were killed in the strike.
"The spot with the peak frequency for big tornadoes is in Oklahoma, right between Dallas and Oklahoma City," Brooks says. "Dallas certainly gets a decided threat."
What would be a long shot for my house alone is a much more likely prospect for some unlucky subset of the Dallas-Fort Worth metro area's 6.3 million people spread across 9,200 square miles. "The target's just getting bigger all the time," says Scott Rae, data application manager for the North Central Texas Council of Governments. "We've been adding 100,000 people a year. What a decade ago would have been a tornado missing in a field is now a tornado hitting a neighborhood."
At the urging of forecasters at the National Weather Service's Fort Worth office, Rae in 2000 constructed a computerized model of the damage path of the Moore twister. He layered the storm's southwest-to-northeast footprint on detailed land-use maps of the D-FW area and chose some 55 different points for the initial touchdown. While the Moore tornado was rated F5, detailed damage-path maps show that it produced F5-level destruction for only a small portion of its 80 minutes on the ground. Most of the way it produced F4- and F3-level damage, meaning, at a minimum, roofs and walls were torn off well-constructed houses.
On those 55 points and "countless other" paths through the Dallas area, the Moore cyclone would cause at least $2 billion in damage. It would hit 30,000 structures, threaten 50,000 people in homes or apartments and trap over 2,000 people on any one backed-up freeway, Rae concluded in his report aptly titled, "The Tornado Damage Risk Assessment: Predicting the Impact of a Big Outbreak in Dallas-Fort Worth, TX." There are many paths in which it would destroy far more, he estimated. If it struck during the workday, buildings containing at least 50,000 people would be in its way.
Marty Nerren, the Dallas Red Cross chapter's emergency planning director, says he used Rae's study, as well as a 2002 threat assessment prepared by Dallas city officials, to arrive at the conclusion that the chapter should plan for 40,000 survivors needing immediate shelter. From the standpoint of planning a response, he says, something Rae's study identified as Scenario 5 provides the most headaches.
In this worst-case scenario, the twister touches down in central Arlington, crosses UT-Arlington, Six Flags Over Texas and Texas Stadium, churns through Irving, across North Dallas and up Central Expressway in Richardson. It finally lifts around East Parker Road on the eastern side of Plano. There aren't many cow pastures on this heavily-populated route. A full 70 percent of the footprint is developed, meaning a whopping 18 square miles of houses, offices, apartments and retail shops would be reduced to bombed-out rubble. Three mobile home parks covering 49 acres also would be pulverized.
In Irving, 3,884 single-family houses would be destroyed, more than 10 percent of its entire single-family housing stock, Rae's report concludes. In Dallas, where the theoretical path would enter the city near Love Field, cross the intersection of Midway and Walnut Hill roads, then cross LBJ Freeway at Hillcrest before entering Richardson, 2,859 single-family houses would be hit with winds strong enough to tear off roofs. Rae estimated that property damage along the entire path would total at least $3 billion using assessed values reported in 2000. Shaw, the Dallas emergency management coordinator, says there is a strong likelihood of fires breaking out along the damage path from ruptured gas lines, no doubt causing further destruction.
Rae's study, which he co-wrote with a researcher from the National Weather Service, did not attempt to estimate casualties in such a nightmare scenario, but Lisius says an estimate worked up informally by several of those involved with the study pegged the likely death toll at 300, with perhaps 5,000 injured. "I'm not with a government organization so I don't need to be as careful," he says. "If it's the evening rush hour and the freeways are backed up, that could make it a lot worse."
It's a given that freeway traffic at any time of day would grind to a halt as people stop under bridges and underpasses to avoid hail or seek what they mistakenly believe will be shelter, says Rae in an interview at his Arlington office. People are most vulnerable in their cars, which can be easily tossed around or pierced by wind-driven projectiles. During the Lancaster tornado, which came with a supercell thunderstorm delivering golf ball-sized hail, thousands of cars backed up on Interstate 20 as people parked under overpasses. There were numerous wrecks as the tornado tore along at a short distance south of the highway.
During the Moore twister, two people died after being blown out from under freeway bridges and 12 people who took shelter under one underpass on I-35 were all badly hurt by flying debris. They suffered injuries ranging from being impaled by a two-by-four, to compound fractures and missing fingers, noses or ears. It took rescue crews a week to find the body of a woman who was killed. She was found about 100 feet down the roadway, under a pile of storm rubble 6 to 8 feet deep.
Since then, the National Oceanic and Atmospheric Association has been trying to disabuse people of the notion that underpasses provide shelter. Its safety studies also warn that climbing up a covered embankment actually puts you into stronger winds higher in the tornado. The agency's recommended course of action for motorists—get out of the car, get low in a ditch and cover your head—hardly sounds like an attractive alternative.
In their house on Highland Drive in Moore, Oklahoma, Marty and Veronia Bernich had been following the twister's progress that evening in urgent TV weather broadcasts. They understood, as the lights went out across their subdivision, that they could be in its path. "I went outside and noticed how serene it was. The sky was all green and yellow," recalled Marty Bernich, a 55-year-old high school art teacher and potter. "My wife started yelling at me to get inside."
TV weather crews had been reporting the twister's extreme intensity, and people were urged to take shelter below ground. Like nearly everyone in his neighborhood, Bernich had no place like that to go. The one-story, three-bedroom red brick and frame house they had bought two years earlier was on a slab foundation with no basement or storm shelter. Most Dallas homeowners would also find themselves with no underground cover.
The couple gathered their two high-school age daughters and two cats between them, hunched down in a windowless hallway and pulled a mattress over their heads. "It sounded just like we were in the first car at the railroad crossing," Bernich says. "You could hear wood splintering. I had a lot of my pottery stored in a garden room, and you could hear it smashing. Then there was this big boom and a pressure change. It felt like the house just imploded."
Ten years later, he can still recall the sound of his daughters' screaming and the feel of things hitting the mattress that they managed to keep over their heads. "It was extremely horrific, but at a certain point I started to feel relief, like I knew we were going to make it," he says. To the smell of freshly dug soil and natural gas, they emerged unhurt and began looking around the wreckage. The entire house, Bernich says, had been twisted off its foundation. That might explain why he felt the sensation at one point of being elevated completely off the ground.
When the couple rebuilt the following year—in another subdivision about three miles away—they had an underground shelter installed, and in 2003 they had a chance to use it when a twister, an F3, hit another part of Moore.
"We were happy to be down there," says Bernich, who has since divorced, remarried and again lives in a house with no shelter.
"My daughters confided to me a few years later that they had nightmares for some time," he says. "When the spring comes, you're living it. You're keeping your eyes open. You go through something like that, and you start paying attention."
After 1999, Oklahoma homeowners built 6,000 residential storm shelters—underground bunkers and above-ground, concrete-reinforced safe rooms—with the help of newly available federal grants. Another grant program later added several thousand more shelters.
Ernst Kiesling, a civil engineer at Texas Tech University and executive director of the National Storm Shelter Association, says he has been promoting the construction of above-ground storm shelters built to tested standards since the early 1970s. "It's only been since Oklahoma in 1999 that people became aware they needed something," he says. "It's been slow to catch on."
Shelters, to the extent they have been built, are thought of as more of a rural necessity. Think Auntie Em and Uncle Henry clambering into their Kansas storm cellar in The Wizard of Oz.
At Tech's Wind Science and Engineering Research Center, which was formed in 1970 following a Lubbock tornado that caused 26 deaths, Kiesling tests the strength of shelters and building materials using a canon that simulates objects being hurled by tornadic winds. A two-by-four shot at 100 mph replicates the force of one carried by 250 mph winds.
Following Hurricane Rita, the Federal Emergency Management Agency began providing Texas with money for disaster mitigation and several local jurisdictions—a group of counties in the Panhandle and another group in the Southern Plains—have used the money to provide individual homeowners up to $3,000 to build high-grade storm shelters. "They just finished building 1,500 shelters in the Panhandle, but for some reason, in Dallas-Fort Worth the idea hasn't evolved," Kiesling says of the program, which has been available for several years.
Asked why Dallas doesn't participate, Shaw, the city emergency official, said in an e-mail that the city has only recently become eligible to participate. "I will have our staff pursue this so that we do apply when the next opportunity presents itself."
It's a good thing I asked. One day, perhaps some future shelter-grant recipient in the city may thank me by inviting my wife and me into their FEMA-funded, Kevlar-lined storm closet when our 5,000 years of favorable odds come to a spectacular end at our house.
Tim Marshall makes no excuses for his fascination with tornadoes, hurricanes and other extraordinary weather phenomena. As a kid growing up in Chicago, he called in weather readings to one of the local stations and was personally affected when on April 21, 1967, an F4 twister touched down four miles from his home in suburban Oak Lawn and tore through Chicago's South Side, killing 33, including a few of his classmates. "I was already a weather kid, a weather nut," Marshall says. "That kind of sealed it."
Educated as a meteorologist and engineer, he has made his living as an expert on storm damage, and he likes to be on location when nature's hammer comes down. "I testify in civil litigation, and it's useful for people to know I was there. Lawyers love the fact that I ride out hurricanes on the Gulf. I'm not just some landlocked engineer from Dallas, Texas," the 52-year-old Marshall explains. "I've seen tens of thousands of homes destroyed in my lifespan. You see the same failures over and over again. They occur routinely."
In tornado-struck areas in Texas and Oklahoma, he has seen a surprising number of single-family homes that were not properly constructed and fail to meet building codes that typically require them to withstand straight-line 90 mph winds. A big strike in the Dallas area would no doubt confirm the extent of the problem, he says.
"Anchors. Braces. Connectors. Those are the three things that are so important that so often I see done wrong," he maintains. "Code says you have to anchor the house to the foundation with bolts every 6 feet. You'll find them without a nut and washer on the bolt, or just a washer, or they skip the bolts all together and use cut nails."
In Arlington, in the two subdivisions that sustained F2 damage in the March 2000 tornado strike that also sent a twister into downtown Fort Worth, Marshall found houses where brick walls weren't anchored to the house frame. "Four out of five houses I looked at had some sort of fatal flaw," he says. Houses with attached garages, the prevailing suburban style, are inherently vulnerable. "You have a door panel, 7-by-16 foot that blows in easily, leaving wind inside your garage. That internal pressure helps pop off the roof from below. I see numerous cases where there was increased damage to houses that had an attached two-car garage."
He adds, "The Three Little Pigs did us a great disservice." Brick houses, or rather frame homes with brick veneer, are easily punctured by tornado debris missiles. And in many cases, he finds houses where the brick was not properly tied to the frame, so the brick walls simply fall down. The nursery rhyme, Marshall says, should have had another verse about steel-reinforced concrete—materials that make interior spaces in high rises one of the better places to weather a violent tornado.
Marshall says he is accustomed to taking heat for his views, which become relevant during insurance disputes and court cases with large damage awards at stake. Over the years, he has been knocked as both a shill for insurance companies—for suggesting that water did most of the damage along the Gulf Coast in Hurricane Katrina—and an enemy of the free market. The later was pinned on him when he advocated requiring mobile home parks in Kansas to provide residents with tornado shelters. The mobile home lobby knocked the idea flat, he says.
For a house hit by an F5 tornado working at full force, even well-fastened anchor bolts wouldn't make a difference. But almost all tornado damage occurs at lesser wind speeds, Marshall says.
Experts spent considerable time debating the strength of the May 27, 1997, tornado that swept through Jarrell, north of Austin, and killed 27 people. Storm-damage photos showing clean-swept foundations where 40 single-family homes once stood lent support to the National Weather Service's official finding that the tornado reached F5 intensity.
But in a report the following year, a team from the federal Building and Fire Research Laboratory concluded that the twister was a tamer F3. Homes in the subdivision, which was located on county land and not regulated by building codes, were poorly constructed, fastened down with nails and likely were knocked down and carried away by lesser winds, the report found.
Government safety warnings, developed from experiences in past tornadoes, instruct people to take shelter in a central, ground-floor room of their house rather than attempt to flee. The risks of taking flight on the roads were borne out in the April 10, 1979, Wichita Falls tornado. Twenty seven of the 42 people killed were attempting to escape the mile-wide wedge funnel in their vehicles.
Advice to stay put worked poorly in Jarrell, but extensive reviews of the Oklahoma F5 suggest it served people well there. Emergency officials in Moore estimate that 2,000 people were in the twister's path and took shelter, like the Bernich family, by huddling low in their house's or apartment's interior rooms. Just three were killed, an outcome federal officials describe as remarkable given the tornado's intensity.
Photos and video footage of the damage show trees stripped to their trunks and houses reduced to lumber piles. But a closer look shows many homes survived with a few interior walls standing—just enough space to furnish shelter. "We found that the majority of people who sought shelter inside their homes survived the tornado without serious injury," says Marshall, who worked with a Texas Tech team surveying the damage. In a report on its findings published in 2002 in the journal "Weather and Forecasting," Marshall wrote that in developed areas, tornado damage begets more tornado damage. "As homes broke apart, their debris impacted neighboring homes, compromising them as well."
Except in rare instances, such as a subdivision that was flattened less than a mile east of where he videotaped the twister, better-built homes survived.
Still, a tornado loose in Dallas with the power of the one he witnessed less than 200 miles from here would be, in his words, "a disaster of unprecedented proportions." And it could happen, adds Marshall. "I hate to Mr. Doom and Gloom about it, but every year without a major strike here just adds to the apathy that is out there."
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