EE #1 was cutting C-Channel steel to remove it, while standing on a 6ft A-Frame ladder while EE #2 supported middle on another 6ft ladder. A piece of slag hit EE #1 causing EE #1 to turn, temporarily blinding EE #2 who stepped off ladder. EE #3 stepped forward to see if EE #2 was okay & steel broke off, fell 10ft. glancing EE #3's hard hat & hitting their shoulder.