EMPLOYEES EXCAVATOR HAD BROKEN DOWN. WHILE ASSISTING A MECHANIC HE CLIMBED UP ON A DOZER BLADE TO RETRIEVE A TOOL. WHEN DESCENDING FROM THE BLADE HE TWISTED HIS KNEES. CONTINUED TO WORK THEN W ENT TO DR ON 12-4-01. MRI COMPLETED, TORN CARTILAGE. SCHEDULED FOR KNEE SURGERY ON 12-3-01.