APPROACHING A BUSY INTERSECTION, MY PONTIAC G5'S BRAKES FAILED TO WORK. I COULD TELL THE HYDRAULICS SYSTEMS WAS WORKING AS I COULD HEAR METAL ON METAL BUT IT DID NOTHING TO SLOW DOWN THE VEHICLE. THE VEHICLE'S CDR SHOWED THE VEHICLE ACCELERATING AT FULL THROTTLE ALTHOUGH I KNOW MY FOOT WAS ON THE BRAKE PEDAL AS EVIDENCED BY THE METAL ON METAL SOUND. PLUS A WITNESS SAW SMOKE COMING FROM MY VEHICLE. I WAS ABLE TO TURN PRIOR TO GOING THROUGH THE INTERSECTION AND AIMED FOR A FIRE HYDRANT TO TRY TO SLOW DOWN. IT DID NOTHING TO SLOW THE VEHICLE, I TRIED TO TURN RIGHT TO JOIN THE TRAFFIC DIRECTION, BUT THE STEERING DID NOT WORK. I THEN HIT ANOTHER VEHICLE. *TR