Apparently they were trying to fix the cartridge and the officer lost control of it and was killed instantly, some of the others dove under the water and surviv

Apparently they were trying to fix the cartridge and the officer lost control of it and was killed instantly, some of the others dove under the water and survived the fire, but as the fire had consumed all the oxygen, it didn't matter. How they figured all that out from what they hauled up, I can only imagine.