You don't have to drive off a bridge to experience the terror of sinking underwater in a car.

Flash floods can be just as deadly — a car could start floating away in only 2 feet of water. Either way, once the water starts pouring into your vehicle, you need to keep your cool while acting quickly.

First, unfasten your seat belt. That may seem obvious, but you'd be surprised at the number of drowning victims who never unbuckled themselves. Then, before the electricity shorts out, roll down the windows.

THAT'S RIGHT, ROLL DOWN THE WINDOWS

This may seem a suicidal act as you sit in a sinking car. But the point is to equalize the water pressure inside and outside the vehicle. If your sinking car stays full of air, there's no way you'll be able to open the door.

If you still can't get the door open and windows won't roll down, find a heavy object, say a flashlight, and break the glass. Don't try to kick out the windshield; you'll never be able to do it. Smash a side window — it breaks more easily if you hit an edge or corner — and swim out through it and head to the surface.

YOUR LAPTOP WILL FORGIVE YOU

Don't waste time trying to gather up valuable possessions. The laptop, the purse, the DVDs ... their time has come. Yours hasn't, if you use your head.