TRAVELLING 45 MPH IN A 55 MPH ZONE ON WET SURFACE. VEHICLE BEGAN TO SPEND OUT OF CONTROL DUE TO A VEHICLE TAPPING THE PASSENGER'S REAR BUMPER. AFTER THE SPINOUT AND CONTACT WITH CEMENT MEDIAN LOSING THE FRONT BUMPER THE TRUCK STOPS. AIRBAG IMPLODES ABOUT 15 SECS AFTER THE ACCIDENT.