An air bag seems simple: When you crash, the bag quickly inflates so that your forward momentum gets arrested by a soft pillow of air instead of the dash, the windshield or the steering wheel.
That is part of how they work. But it actually goes beyond that.
For one thing, the air bag spreads out the impact. Instead of all of your force driving into the first body part to make contact -- your forehead hitting the dash, for instance -- the entire upper part of your body hits the air bag. This spreads out the same energy, so it's not as focused and dangerous.
On top of that, air bags stretch the impact out. It takes longer for your body to move through the same physical space. This also robs the impact of some of its energy. The goal of the air bag is to take your body from 60 miles per hour to zero miles per hour in a gradual motion, rather than all at once. The air bag doesn't just inflate and catch you. It deflates to reduce your speed.
Air bags can be very helpful, and they do save lives. Unfortunately, they are not perfect. Some people still pass away in accidents where their air bags worked perfectly. Others die when they have defective air bags that do not protect them at all.
If you lose a loved one in a crash like this, you need to know what rights you have to financial compensation, which can help cover for things like funeral costs, medical bills, lost wages, lost future earnings and a lot more.