EE WAS INSTALLING A R-BOLT TO REPLACE ONE THAT HAD BEEN DAMAGED. WHEN HE STARTING DRILLING A SECTION OF THE ROOF 0"" TO 3 FT. WIDE BY 0"" TO 1 1/2 "" THICK FELL ON THE CANOPY PART OF IT BROKE OFF AND STRUCK HIM ON THE BACK, HE REFUSED AN AMBULANCE AND TRANSPORTED HIMSELF TO THE DR.