Loose grip on grinder-grinding tack weld to finish weld crack on truck dump box, disk caught in crack, kicked grinder back, knocked PPE off, grinder struck chin, lip, nose & left side of face. 1 1/2"" cut chin to lip-10 stitches, abrasion left cheek, broken nose-will need surgery to align, many fractures to cheek bone-no further medical unless complications occur.