Friday, December 07, 2007

Tornado Tragedy

March 1, 2007 was an unusually warm day in Enterprise, Alabama, a small community in the southeastern part of the state. With temperatures expected to top 70 degrees and humidity over 60 percent, it was a sign that spring was just around the corner. For students at the local high school, the warm weather and a scheduled early dismissal couldn't come at a better time.

Unfortunately, that balmy, humid atmosphere was a harbinger of change, the proverbial calm before the storm as a powerful cold front swept across the region. The front, which would stretch from Minnesota to the Gulf Coast, was being pushed eastward by a ferocious Jet Stream.

Those gusty upper level winds would spawn more than 31 tornadoes across several states including a huge twister that struck Enterprise High School, killing eight students and injuring dozens more. The twister collapsed concrete walls, overturned cars in the school's parking lot and ripped apart the football stadium.

The tornado was 500 yards wide, on the ground for 10 miles and produced winds of 170 mph. It was the first killer tornado at a school since 1990 and the deadliest single twister in the United States in 40 years.

At first, school administrators came under some criticism for not dismissing the students early. Residents near the high school said they had heard warning sirens long before the tornado slammed into the high school, and school officials admit being told of the tornado threat three hours in advance.

But administrators at Enterprise High School said the weather was too violent to let the students leave the building, and they were worried that canceling classes would lead to even more carnage if the students were outside the high school when the tornado struck.

“I don't know of anything they didn't do," Alabama Governor Bob Riley told reporters after touring the damage. "If I had been there, I hope I would have done as well as they did."

Now, a six month long assessment by the National Weather Service agrees, concluding that high school officials and students followed appropriate safety measures during the tornado outbreak.

“Dismissing the students could have been just as dangerous,” said Glenn Lussky, the assessment team leader “Tornado warnings were in place the entire time, and the team agreed that shelter in place was the best response.” The report says the eight fatalities at the school were due to structural failure of the roof and walls, not the decision of the administrators.

Still, Lusky’s team says that shelter, in this case Enterprise High School, needs to have hardened safe rooms to survive future tornadoes. A hardened safe room, lined and topped with concrete, and without windows is designed to survive severe sustained winds and high wind gusts.

While a tornado the size and intensity that hit Enterprise, Alabama is virtually impossible in South Florida, comparable winds have occurred with hurricanes. In 1992, Hurricane Andrew produced sustained winds of 165 mph as it tore through southern Miami-Dade County.

More than $25 billion in damages and hundreds of destroyed homes led to new, tougher building codes. In recent years, all new schools built in the area have hardened safe rooms to act as shelters during periods of evacuations. Lusky’s team would like to see that trend grow around the country, especially in areas susceptible to large, powerful tornadoes.

“The tragic events of March 1 show that even when people have ample time and opportunity to take cover from a devastating tornado, the need for proper shelter is imperative,” said Conrad C. Lautenbacher, the head of the National Weather Service. “Despite warning lead times that exceeded national standards, many lives were lost. Our team concluded that survival in violent tornadoes often depends on reaching an adequate hardened safe room.”

Thanks to Frances, Jeanne and Wilma the term “safe room” is well known here in South Florida. Lusky and the folks at the National Weather Service would like that phrase to be commonplace around the country, too.

Posted at 12:36 PM