Subsequent investigation revealed that just before the explosion in "Doterel", two men had been sent to clean the leaking explosive liquid from beneath the forward magazine and may have broken the rule of not having an open flame below decks.
Two men had been sent to clean the leaking explosive liquid from beneath the forward magazine. This was just before the explosion in "Doterel". This was what subsequent investigation revealed. Subsequent investigation may have broken the rule of not having an open flame below decks.