Aug. 3, 2007 — -- Plunging 60 feet off a bridge in a car sounds like a sure death sentence, but survival experts say people can and do walk away from such a calamity, for a simple reason: They were wearing their seat belts.
"The people who got out without a scratch absolutely had their seat belts on," says Brian Brawdy, survival expert and a former New York City police officer. "If you're knocked unconscious because you weren't wearing your seat belt, you won't be swimming to the surface."
Kimberly Brown, who survived the bridge collapse, told "Good Morning America's" Robin Roberts that had she not been wearing her seat belt, she was certain she would have gone through her car's windshield.
With four confirmed fatalities, Minneapolis authorities say they expect the death toll to rise as vehicles' that fell more than 60 feet into the Mississippi River are recovered.
Chances of surviving for those still submerged in the river now almost 24 hours later are remote, experts say. The combination of the impact and the speed at which cars sink give passengers mere minutes to avoid suffocation.
"[Drivers] would have three to five minutes, depending on how much of the water is rushing in and then given the size of the car," says Brawdy.
While many people may assume that unbuckling a seat belt and attempting to escape is the first thing to do in a sinking car, experts say otherwise.
"You want to make sure the impact is over before you take off your seat belt," says Brawdy, who warns that drivers and passengers should be certain no other car or foreign object is heading toward their vehicle.
In addition to remaining buckled up, here's some other tips to maximize your chances of escaping from a sinking car.
The weight of the engine will make the car nosedive into the water, and with water quickly surrounding the vehicle, passengers must allow the pressure to equalize before they waste their energy trying to open the doors or windows.
"You have to wait for some of the water to get in the car to equalize the pressure," says Brawdy. "You won't be able to open the door, and as counterintuitive as it sounds, you've got to let some water come in."
"Wait until the water gets up to your sternum and that's the time to take as deep a breath as you can," he says. "The water pressure would have started to balance itself out and you're going to be able to swim out."
While waiting for your car to fill with water is certainly panic-inducing, experts say panicking could severely diminish your chances of survival. Staying calm and preserving your energy and breath for when you have to swim out will make a huge difference.
"If you panic, you perish," says Brawdy. "Taking deep breathes is as important as anything. It calms your body. We are using energy when we panic, and then we become tired."
Losing your composure during a crisis situation will hinder your ability to make decisions that could ultimately be your key to survival.
"You've got to think methodically," says Lt. Joseph Conway of the Dive Team at the Madison, Wis., Fire Department. "Otherwise, what happens first is you'll hit the water and then you'll try to get out and you'll forget you didn't unbuckle your seat belt. "
Many of those who fear suffocating in a sinking car are under false pretenses about what exactly happens when your car lands in water, as well as what the best ways to get out are.
"The car takes longer to sink than we think," says Adam Savage, co-host of Discovery Channel's "Mythbusters," which aired a segment on how to escape a sinking car. "We had time to try to unroll the window and open the door."
Another myth about sinking cars is that the car's battery will immediately fail when it hits the water. Savage says that people should still try to work the electric controls for the windows.
"People think the batteries will short out, but they won't," he says. "You easily have a couple of minutes, even if you're submerged, when the batteries will still work."
People commonly use the wrong tools and expend too much energy trying to break windows, Savage explains.
"Breaking the window with anything but special tools failed," says Savage, who tested different methods while submerged in a swimming pool. "Steel-toe boots and a multitool had no effect on the window, but a special hammer tool worked like a charm."
There are several of these tools on the market. ThinkGeek, an electronic commerce company based in Fairfax, VA, has created a 5-in-1 tool called, The BodyGuard, which can break glass and cut seatbelts and has an alarm, a flashing red light and an LED flashlight. The ResQMe keychain is a similar device. The Life Hammer is designed to shatter glass and strip seatbelts.
There's something else besides pressure though that might make windows difficult to break, according to AAA spokesman Robert Sinclair: window lamination.
"There is a trend among manufacturers to laminate the side glass windows to cut wind noise and make the interior quieter," Sinclair said. "But when you need to break the glass ... if that side glass is laminated it's going to be much more difficult to escape."
The biggest culprits, Sinclair says, are SUVs.
"They tend to be the one using laminated side glass more and more," he said.
But If you don't have a special window-breaking tool, improvising may also work.
"The thing you do is you can't hit it with your fist or a blunt object -- a sharp-pointed object is the best for a side window," says Conway. "You see people kicking, and they're just going to expend their energy."
Ashley Phillips and Thomas Dilworth contributed to this report.