INJURED EE WAS PART OF A BUCKET BRIGADE PASSING 5 GAL PLASTIC BUCKET FILLED WITH RUBBLE AND DEBRIS THAT HAD BEEN REMOVED FROM THE INSIDE OF THE PREHEAT DOOR DUCTS AND VESSELS. AS HE PASSED A B UCKET HE FELT A STRAIN IN HIS LOWER BACK. AN INCESTIGATION FOUND TWISTING OF THE TORSO.