What happens to an air bag during a car crash?

A accelerometer sensor on the vehicle sends a signal to the airbag to inflate when you have an accident equal to hitting a brick wall at 10-15 mph. The airbag inflation system gets the signal and this causes sodium azide to mix with potassium nitrate which produces nitrogen gas. The sudden blast of gas inflates the airbag at 200 mph. A second later the airbag deflates through tiny holes in the bag. This inflation happens in one-twenty-fifth of a second. The powdery substance left is cornstarch or talcum powder use to keep the bag pliable and lubricated during storage.