[Snautzer]

There were places where the crew can store there parachutes (see pic). I think the crew except the pilot ( he would be sitting on his I think) would store their chute during non combat flight or when the commander felt it was safe to do so.

So perhaps in your plane, there was a major malfunction in an otherwise un-eventfull flight and the rest of the crew did not have time to put on their chutes.

According to protocol no jumping out of the bomb bay see pic 2 and 3 but designated places in the airplane.