You might find this one interesting and emphasizes the need to lock out the main CO2 valves during work. Two men in the engine room (One a Coast Guard inspector) were killed. It was a result of a screwup on the part of Hiller Systems (while conducting an authorized post-repair test) and I personally know people who will not allow Hiller systems on board their ships to this day as a result of it. Incidentally, I used to work for one of their biggest competitors.