DRIVING DOWN THE INTERSTATE AT APPROXIMATELY 70 MPH WHEN THE VEHICLES IN FRONT OF THE TRUCK SLAMMED ON BRAKES. I WAS ROUGHLY 30 FT BEHIND THE VEHICLE IN FRONT OF ME. I SLAMMED ON MY BRAKES AND THE PEDAL FELT SPONGY BEFORE GOING TO THE FLOOR. THE TIRES DID NOT LOCK UP, AND THE TRUCK SLOWED 20MPH IN ABOUT 30 FT. THE TRUCK MADE IMPACT WITH A CHEVROLET TAHOE AT 50 MPH. THE AIRBAGS FAILED TO DEPLOY AND THE SEATBELT FAILED TO LOCK, THROWING MY KNEES INTO THE DASH. THE CHEVROLET TAHOE WAS TOTALED. THE CURRENT ESTIMATE TO REPAIR THE RAM IS $5,448. THE BUMPER, DRIVER FENDER, GRILLE, AND HOOD WERE DAMAGED. UPON REMOVING THOSE ITEMS THE SHOP FOUND ALMOST EVERY BRACKET IN THE FRONT END HAD BEEN BROKEN AND THE FRAME HORNS BENT UPWARDS FROM THE COLLISION. THE IMPACT WAS HARD ENOUGH TO BREAK A RATCHET STRAP IN THE BED OF THE TRUCK, SENDING A LADDER THAT I WAS CARRYING INTO THE CAB CORNER, LEAVING A SOFTBALL SIZED DENT. WE WERE ABLE TO DRIVE AWAY FROM THE INCIDENT AND THE BRAKES WERE FUNCTIONAL ON THE TRIP TO THE BODY SHOP, HOWEVER ANY ATTEMPT TO DEPRESS THE PEDAL RAPIDLY WOULD RESULT IN A SPONGY PEDAL. MILEAGE AT THE TIME OF THE INCIDENT WAS 81,110. RAM WAS CONTACTED AND AFTER A WEEK OF BACK AND FORTH RAM AGREED TO SEND SOMEONE TO INSPECT THE VEHICLE TO DETERMINE IF THERE IS A FAULT IN THE TRUCK.