CO RIGHT-4 NORTH. TIGHTENING WATER HOSE COUPLER WITH PIPE WRENCH, SLIPPED & HIT KNUCKLE ON TOP. ACCIDENT DID INVOLVE ASPECT OF COMPANY POLICY BUT NOT REGULATIONS. DIDN'T INVOLVE MINING SYSTEM. ACCIDENT DID INVOLVE JOB SKILLS, MINER PROFIENCY TRAINING BUT NOT ATTITUDE. ACCIDENT DID INVOLVE PROTECTIVE CLOTHING.