JOPLIN, Mo. — A devoted cadre of scientists bent on untangling information and explanations from the debris has toured Joplin, hoping to learn some lessons from the rubble about surviving tornadoes such as the one that hit May 22.

Three researchers from Iowa — Bill Gallus, Partha Sarkar and Chris Karstens — focus on structural damage.

They want to know why some people lived and others died, and why this tornado was among the deadliest in history.

The short answer: The country needs better buildings to ensure that houses, schools and businesses can bear the brunt of these violent storms. Hiding in a hallway just doesn’t cut it. And it’s about more than saving lives, although that is a prime focus.

“Schools, hospitals, other essential structures — we cannot afford to lose them,” said Sarkar. Especially not in a storm. “These are places people go to for help.”

The May 22 tornado destroyed several schools, incapacitated one hospital and wrecked at least two fire stations.

Natural cycle

EF-5 tornadoes are the most powerful and most destructive of tornadoes — and also fairly rare. On average, there are more than 1,200 tornadoes every year in the United States. Yet the Storm Prediction Center in Oklahoma has logged only 56 EF-5s since 1950. There have been four this year — including Joplin’s and three others in late April.

EF-5s “are born at 65,000 feet,” said Sarkar, spawned in the clash involving cool air from the north; humid, warm air from the Gulf of Mexico; and dry air from the west. This spring, there has been a historic snowpack in the northwestern United States, drought in the Southwest and warmer-than-normal water in the Gulf of Mexico.

A likely major factor in this year’s tornadic outbreaks is La Nina, the periodic cooling of the Pacific Ocean that controls the jet stream and is part of the planet’s natural cyclical process, said Steve Runnels, the National Weather Service’s warning coordination meteorologist in Springfield. La Nina years are typically above average for tornadoes, including violent ones. In contrast, El Nino brings warmer-than-normal currents in the Pacific.

While some studies have suggested that global warming could cause more and stronger storms, National Weather Service Director Jack Hayes isn’t ready to blame isolated storms on climate change — “at least not yet.”

‘Creepy’

Although EF-5s are rare, they have hit cities before, including Topeka, Kan., and Waco, Texas. But Joplin’s tornado did some things that haven’t been seen by these Iowa State researchers — or their peers from Texas Tech and other universities who were in town in the days after May 22.

The researchers study how wind moves across landscapes. Because they are scientists, where others see shattered buildings and piles of debris, they see stories.

Some of what they saw in Joplin surprised them: The shifting of a hospital from its foundation. Oversized manhole and storm sewer covers sucked off the ground. Concrete tire stops pushed several feet off their rebar pins. A two-by-four that passed through multiple walls and embedded itself in a school office. A student’s chair at the high school lifted high into the air, tangled within ceiling wires.

“As a parent, that was creepy,” Gallus said.

Like many “extremely violent” tornadoes, this was a multi-vortex with several “fingers” spinning around the larger center — but its movement was unusual, Runnels said. Multi-vortex funnels often “skip” along the ground at a good clip, creating an “intermittent path,” he said.

In contrast, the path of Joplin’s tornado was slow and steady for the 13.8 miles it was on the ground.

“It remained on the ground the entire length of Joplin,” Runnels said. “That led to it being more destructive.”

Safe rooms

The researchers say enhancing storm survivability is a matter of priorities — for individuals, community leaders and others. The usual objection to requiring enhanced building codes is the cost: Why make homeowners and business owners pay for safety features that might never be used?

“But then, why put an air bag in a car?” asked Sarkar, a wind engineer and professor at Iowa State.

Gallus, a professor of atmospheric science at ISU, was emphatic: “I would not move into a house if it did not have a safe room.”

He realizes that most people would rather put their money into a granite kitchen countertop than invest in Federal Emergency Management Agency-approved “hardened” walls that can withstand flying two-by-fours and other hazards.

But Sarkar said building a room where people can hide isn’t enough.

“It’s like Noah’s Ark,” he said. “You come out of your safe room, and your house is gone. Your neighbor’s house is gone. Your neighborhood is gone. Your work is gone. What do you have?”

Instead, Sarkar would like to see more tornado-resistant housing — allowing entire neighborhoods and communities to survive, and not just individuals.

The new housing priority, Sarkar said, should be smaller, better designed and better built homes that are closely inspected during construction.

What bothers the Iowa State team members most is the damage, destruction and loss of life that they say could be prevented, based on existing technology.

Even the simple addition of hurricane straps — reinforcements that connect rafters to wall studs — to conventional home construction can help a home stand up to 140 mph winds, they say.

The Iowa State researchers have received multiple grants from the National Science Foundation, and the National Oceanic and Atmospheric Administration to determine exactly what it takes to improve building integrity and safety under a variety of conditions.

While there are no guarantees, they say, doing some of these things — putting in a safe room, using hurricane straps — boosts the odds.

“The average person in the USA thinks that if I follow the safety tips, I won’t die,” said Sarkar, president of the American Association for Wind Engineering. “But that only improves their chances.”

‘Some degree of luck’

No matter how well-protected people thought they were, their homes were by and large no match for the EF-5. Some were blown as much as 10 feet off their foundations. Cars were lifted off the ground and dropped on roofs.

In a storm such as that, there is “some degree of luck” to surviving an EF-5, said Runnels, with the National Weather Service. There were people in third-floor bathrooms who emerged to find every other room gone, and there were people who found shelter in basements then died when the building fell in on them.

While there are no guarantees in a storm that can shift concrete parking stops secured to the ground with rebar, the best way to improve the odds of survival, Runnels said, is to have a storm shelter and a plan, and to take warnings seriously.

Warnings are another key part of what happened that day.

There actually were two: the first at 5:11, according to the city, and the second about 15 minutes later.

Keith Stammer, director of emergency management for Joplin and Jasper County, said the sirens are designed to warn people outside of approaching danger. They are not necessarily intended to warn people inside houses. Houses are built too tight today, and too many people have too many electronics going or ear buds in to hear the sirens when they are indoors.

Stammer said the best heads-up for people in a home is a weather radio, which can send a loud signal throughout a house day or night when severe weather is imminent, and can trip on automatically to relay details about a watch or warning.

The federal Storm Prediction Center highlighted Southwest Missouri as having the potential for severe weather several days before Joplin’s storm. It also issued a tornado watch more than four hours in advance of the tornado touching down. The first warning was issued about 30 minutes before the tornado first hit the city limits.

Studies show that for tornado warnings, 15 to 20 minutes is the most effective; longer advance warnings actually can increase deaths. It appears to be natural to think that if a twister hasn’t appeared in that amount of time, it must have been a false alarm.

But for some people, a 20-minute warning may not be enough.

“If you have a basement, you don’t need 20 minutes’ warning, but if you are in a mobile home park, you may need more than 20 minutes to find a shelter,” said Alan W. Black, co-author of a recent study of tornado and wind fatalities.

School shelters

Although there are many homes in Joplin without basements — due in part to the rocky terrain and high water table — some rebuilding efforts already have begun to raise questions about what steps need to be taken, particularly with public buildings.

Rebuilding efforts have begun for the Joplin School District. Three school buildings were slammed, including the high school; three more were severely damaged; and two others have roof damage.

One side of Joplin High School was so badly mangled that school officials didn’t even recognize it when they first saw it.

Superintendent C.J. Huff said in the first days after the storm that he already had “reached out to FEMA to seize the opportunity” to put tornado-resistant storm shelters in every school building in the district. “We are committed to this,” he said.

FEMA provides a limited amount of funding to school districts for such projects after storm damage has made an area eligible. For example, Wichita (Kan.) Public Schools received funding to provide shelters at three buildings. The district later extended the project and now has more than 45, with still more under construction.

FEMA-approved school shelters also can serve as libraries, gymnasiums, multipurpose rooms or fine-arts suites. They have walls of steel-reinforced concrete 10 to 12 inches thick. The design and construction make them strong enough to withstand an EF-5 tornado’s winds of more than 200 mph — and the accompanying debris.

FEMA says it funds such projects because school corridors “typically have construction features that make them unacceptable as storm shelters. The walls usually are not constructed to resist winds from a tornado because stud walls or non-reinforced masonry units are used.

“The roof structure over the corridor can be lightweight and may be prone to collapse in a severe wind.”

The Associated Press contributed to this report.



Urban sprawl

Marshall Shepherd, a professor of atmospheric science at the University of Georgia, believes the growth of cities — urban sprawl — plays a factor in the rising number of tornado deaths this year.

Tornadoes have always crossed farmland and other rural areas doing little damage, but as cities increase the land area covered by homes and businesses, “you’re increasing the size of the dartboard,” Shepherd said.

A century ago, Joplin covered 12.5 square miles. Nowadays Joplin — home to more than 50,000 people — is nearly three times as big, at 35 square miles, tripling the odds of being in the way of a big storm.