WHILE HELPING REPAIR 14CM MINER HE TRIPPED OVER RUBRAIL AND FELL AGAINST THE PANEL BOX INJURING HIS LEFT RIB AREA. AT THE TIME HE DID NOT THINK IT WAS SERIOUS SO HE DID NOT REPORT IT. HE THEN FELT PAIN IN HIS LEFT CHEST AND RIBS AND A SHORTNESS OF BREATH. TAKEN TO HOSPITAL WHERE EKG WAS PERFORMED & DETERMINED NOT TO BE A HEART ATTACK.X-RAYS DETERMINED A TORN MEMBRANE IN LEFT CHEST.