2013 Chevrolet Cruze brakes problems

I was driving about 35 MPH on a city street when the person in front of me slammed on their brakes the first time I hit the brake and the car stopped the next time I hit the brake it was hard and didn't stop the car causing me to crash into the vehicle in front of me, the air bag did not deploy and I think it should have, causing my head to slam into the steering wheel causing me to bite my tongue in half.

The contact owns a 2013 Chevrolet Cruze. The contact stated while her husband was reversing from a parking space with her in the front passenger seat, he depressed the brake pedal but the brake pedal failed to respond, causing the vehicle to continuously reverse. The contact stated that her husband continuously depressed the brake pedal until it responded; however, the vehicle hit the rear passenger side bumper of a parked unoccupied vehicle. The contact stated that it was a fender bender.