I am reading a diary of a B17 co-pilot. He flew in 1944. The conditions and combat that B17 crews went through were absolutely horrible. He talks about gunners getting their face and jaws blown off by cannon shells, guys chests being ripped open and lungs being exposed, entire crews being burned alive in explosions. Very vivid descriptions. But the most vivid account is at the very end of the book. The author of the book was KIA 1944 enroute to Lepzig, Germany.