EE WAS MOUNTING THE REAR OF A MOTORGRADER TO CHECK THE ANTIFREEZE LEVEL HIS LEFT FOOT SLIPPED OFF THE REAR STEP CAUSING HIS LOWER LEFT LEG TO COME IN CONTACT WITH A VALVE THIS FORCED HIS LEG TO BEND BACK FURTHER THAN IT NORMALLY COULD CAUSING PAIN & SWELLING IN HIS LEFT KNEE BY 5/4/00 AT WHICH TIME 1ST AID WAS GIVEN. MED EVAUATION 5/19/00 MRI 5/31/00 DIAGNOSED TORN LIGAMENT