Many serious accidents have happened when someone thought a machine or the power to it was safely off.
On a balmy spring afternoon in 1994, a 3,700-pound industrial table broke from its temporary tether and crushed Jerry Butcher to death. Butcher, a millwright for Ravenswood Aluminum Corp., had been repairing a hydraulic cylinder hose under the improperly secured table when it dropped. OSHA cited the West Virginia plant for alleged lockout/tagout violations and proposed penalties of $2.1 million.
Many workplace accidents are caused by machinery that accidentally becomes activated while being serviced or maintained. This accidental activation is called an [uncontrolled released hazardous energy." Many of these accidents can be prevented if the energy sources are isolated, and locked or tagged out.