EMPLOYEE WAS PUTTING 4"" WATERLINE TOGETHER USING A CRIB BLOCK. WHEN HE PULLED BACK A CRIB BLOCK TO BUMP THE WATERLINE TOGETHER IT SLIPPED OUT OF HIS HAND & THE CORNER OF THE CRIB LANDED ON TOP OF HIS LEFT FOOT AT THE EDGE OF HIS METATARSAL BOOT. HE FINISHED HIS SHIFT THEN WENT TO THE DOCTOR.