EE WAS BOLTING ON THE TRUSS BOLTER TO CATCH UP ON THE BOLTING. HE HAD DRILLED THE HOLE IN THE ROOF & TRAMMED UP TO PLACE HIS HAND ON TOP OF THE WRENCH & THE BOTTOM OF THE DRILL STEEL. HE WAS LOWERING THE DRILL BUT HEARD SOMETHING BY HIS TRAY & WHEN HE LOOKED AT THE TRAY MUST HAVE HIT THE FEED UP LEVER. THIS SMASHED HIS INDEX FINGER &THUMB BETWEEN THE ROOF & THE TOP OF THE WRENCH.