3 EAST MAINS-#2 ENTRY: AFTER INSTALLING THE 1ST ROW OF BOLTS & ADVANCING THE ATRS, EE OBSERVED A LOOSE SECTION OF ROOF BETWEEN THE ATRS & THE CANOPY. WHEN HE PULLED THE ROCK DOWN A 2ND PIECE FELL AS WELL. THE 2ND PIECE GLANCED OFF THE MACHINE & HIT HIS LEFT FOOT BEHIND METATARSAL GUARD.