An arc blast really hurt a guy out here in NJ. To make matters worse, the room had a bunch of combustables stored in it (mainly cardboard). Here's the article from the Newark Star Ledger:

An electrician severely burned in a fire at Plainfield High School remains in critical condition with "life-threatening" injuries, his family said yesterday.

Ollie Johnson, 68, sustained third-degree burns over 80 percent of his body and is in a drug-induced coma at St. Barnabas Medical Center in Livingston, according to his daughter, Lisa Johnson.

Johnson was working in an electrical room when some equipment became energized and caused an explosion just after 9 a.m. Saturday, fire Battalion Chief Richard Polunas said.