On Wednesday 4th October 2006, at about 1700hours, a five-man cleaning crew was cleaning a concrete mixer unit at the premises of a Coating Contractor. The cleaning takes place at the close of work. Prior to the actual cleaning work, the power supply to the concrete mixer motors should be isolated at three points. A Lock Out Tag Out (LOTO) procedure exists for the cleaning operation. There were three switches required to be activated to start the mixer motors. Anyone going into the mixer must carry the key of the third switch along, after switching off the motors and locking the panel. On this day the panel door for the switch that ensures the mixer motors cannot start was not locked. The machine was switched on in error by one of the cleaners, resulting in the death of two persons and injury to two others. The four victims had been cleaning the internals of the mixer.The cleaning process requires the cleaners to physically get into the confined space and chip away dried concrete off the mixer blades and walls. One of the two injured persons later died as a result of the injuries sustained in the accident.