Investigators believe the most probable cause of the accident was the sudden introduction of feed water to the boiler that at the time of the explosion was operating in a dry-fired state.
The report indicates Leslie Evans, the maintenance worker who was injured in the explosion, entered the boiler room and found that one of the boilers was in a low water condition while the other was at full fire, but also in a low water condition.
Feed water was introduced back to the boilers, and the second boiler exploded.
Investigators have not determined whether Evans started this process himself by putting water into the boiler.