HUSBAND WAS TRAVELING UNDER 25 MPH UP HILL AND TWO VEHICLES AHEAD OF HIM ABRUPTLY STOPPED FOR UNKNOWN REASON WHICH RESULTED IN THE VEHICLE IN FRONT DOING THE SAME CAUSING MY HUSBAND HAVING TO HARD BRAKE. AS HE TRIED TO STOP THE VEHICLE THE BRAKES WOULDN'T RESPOND AND CAR KEPT ROLLING RESULTING IN AN ACCIDENT. THE ABS CONTROLLER FAILED