EMPLOYEE WAS WORKING ON TOP OF AN INSULATED BAG HOUSE. HE WAS KNEELING ON THE OUTER METAL SKIN. ONE OF THE GALVANIZED TABS WHICH HOLDS THE INSULATION IN PLACE UNDER THE SKIN HAD APPARENTLY BEE N CUT OFF SHORT INSTEAD OF BENT OVER DURING CONSTRUCTION. THIS SHORT METAL SPIKE PUNCTURED THE OUTER SKIN WHERE THE EMPLOYEE WAS KNEELING AND ENTERED HIS KNEE UP UNDER THE KNEECAP.