WHILE DRIVING AT ABOUT 25-30 MPH CONSUMER APPLIED BRAKE, CAR ACCELERATED UP TO 80 MPH. HIT 2 VEHICLES AND A TREE BEFORE COMING TO STOP. AIR BAGS DID NOT DEPLOY. CONSUMER TOOK KEY OUT OF IGNITION, DID NOT STOP MOTOR FROM RUNNING, FIRE DEPARTMENT SHUT ENGINE OFF BY BLOCKING TAIL PIPE, THEN DISCONNECTED BATTERY. TOOK TO DEALER, TOTAL LOSS, CONTACTED CHEVROLET, WAS GIVEN REQUEST NUMBER, BUT HAS NOT HEARD BACK. *AK ONE PERSON WAS INJURED IN ACCIDENT. *SLC