2002 Chevrolet Blazer brakes problems

To avoid accident on 2002 chev blazer 4wd. I was in 2wd I hit the brakes. Nothing happened. I pushed brake pedal as far as it would go. Seat belts did not tighten, I downshifted but nothing happened. I heard two clunks in the rear end. I was unable to slow down from my speed at 30 MPH. I saw a warning light on the dash during this incident. I hit a pickup truck who stopped suddenly to avoid a senior citizen who crossed lanes of traffic in a 65 MPH she was doing about 30 MPH.

Tl* the contact owns a 2002 chevrolet blazer. The contact stated that the driver's side door hinge failed to close, an abnormal humming noise was detected, the vehicle rocked, and a tire blew out. In addition, the ABS, air bag, and parking brake warning indicators illuminated. The vehicle was taken to tom joyce automotive (18260 paulson dr, unit d3, port charlotte, fl 33954) where it was diagnosed that the door, pins, and hinge needed to be replaced. The vehicle was repaired; however, the failure recurred.