(CNN) -


Emergency officials have long held that you should just stay put if you're inside anything other than a mobile home -- and head for the lowest floor and the inner-most room.

Yet even with improvements to severe weather prediction, no one can say with certainty what a tornado will do.

In Moore, Oklahoma, a woman and her brother took shelter inside their restaurant's walk-in freezer and survived. Another woman and her baby did the same thing at a convenience store -- and died.

Terimy Miller initially put her three sons into a closet but changed her mind when she turned on the TV and heard a reporter talking about her neighborhood.

"He said, 'Get out now if you have no shelter. If you have shelter, get in it. But if you don't, get out ... it's not safe. Go! It's too huge!'"

So Miller put the boys -- 6, 7 and 11 -- into her car and drove off, her radio on.

"They said, 'It's getting right close to 19th and 4th," she recalled. "I said, 'Boys, it's right behind us! You can see it, you can see it!' "

She steered out of its path, escaping unharmed. When she returned, her home -- closet and all -- was destroyed.

Another woman who hid inside her closet survived unharmed after the closet door landed on top of her and protected her.

Outrunning the storm?

While the most common advice is to shelter in place, some experts say it may sometimes be smart to do what Miller did -- get into a car and drive -- especially if you have enough warning.

"You rarely ever have less than 15 minutes, and usually considerably more," said Ed Bates, an architect who designs buildings that incorporate storm shelters.

"With the good lead time, I'd tell people to get in their automobile and go 90 degrees from that perceived path," said Bates. "It's manageable and easy to do -- even in a city environment."

Given open roads and a reliable vehicle, the race should not be close. Funnel clouds can travel as fast as 70 mph, but their average forward speed is only 30 mph, according to FEMA.

The tornado that ripped through Moore on Monday was one of the strongest on record, with winds topping 200 mph. Twenty-four people were killed, 10 of them children. Hundreds more were injured.

The twister damaged or destroyed about 12,000 homes, and state insurance adjusters expect the claims to exceed $2 billion.

Aerial views of what's left of the Oklahoma City suburb testify to the danger courted by those who sheltered in place.

Residents of Moore had 36 minutes from the time the National Weather Service issued its warning until the time the twister entered the city.

But even that lead time would not necessarily have persuaded Ernst Kiesling to try to race out of harm's way.

"It's a tough question," said Kiesling, a civil engineering professor at Texas Tech University who has spent his life studying tornadoes and developing above-ground storm shelters to protect against them.



