THE INJURED WORKER SLIPPED ON AN OILY SURFACE WHERE HE WAS STANDING TO REPLACE THE LEAKING SEAL AND TWISTED HIS LEFT KNEE. HE DID NOT REPORT THE INJURY FOR A FEW DAYS AS HE THOUGHT IT WAS A MINOR INJURY. AFTER DR VISIT & AND MRI IT WAS DETERMINED THAT SURGERY WOULD BE REQUIRED TO HIS KNEE. THIS WAS DETERMINED ON 11/3/05.