EE WAS SPLITTING A LARGE SLAB OF SANDSTONE WITH A SLEDGE. THE SLAB WAS POSITIONED HORIZONTALLY ON THE GROUND. AS EE STRUCK NEAR THE EDGE OF THE SLAB, A PIECE OF STONE PROJECTED OFF THE SLAB STRIKING THE CALF OF LEFT LEG. INJURY WAS NOT REPORTED UNTIL 040105, MEDICAL DIAGNOSIS WAS CONTUSION TIBIAL AREA. LOST 1 WORK DAY 040105