EE WAS TAKING DOOR OFF OF DUST BIN, DUST HAD BUILT UP BEHIND DOOR UNKNOWN TO EE. WHEN DOOR WAS LOOSENED DUST ESCAPED AND BROUGHT VISIBILITY TO ZERO. AS EE CLIMBED DOWN LADDER TO ESCAPER DUST, HE SLIPPED OFF A LADDER RUNG AND WHEN HE LANDED ON THE CONCRETE HE HIT WITH HIS LEFT SHOULDER FIRST, CAUSING INJURY.