VEHICLE WAS PARKED FLAT IN A PARKING LOT, JACK WAS LEVEL AND ON ASPHALT. VEHICLE WAS JACKED UP AND TIRE REMOVED. AFTER TIRE WAS REMOVED, JACK BROKE APART AND TRUCK FELL TO THE GROUND LANDING ON ROTOR ASSEMBLY. VEHICLE GRAZED MY LEG, AND FRIENDS LEG AS IT WAS FALLING TO THE GROUND. *AK