Two 305th Bomb Group B-17 Flying Fortresses collided in mid-air in heavy fog over Thurleigh airbase after returning from a mission; both were destroyed with all hands lost. Handwritten caption on reverse: '55819.' Printed caption on reverse: '55819 AC - Returning from a daylight bombing assault on important synthetic oil plants and key communications centers just behind von Rundstedt's lines, two B-17 Flying Fortresses collide in mid-air and disintegrate. None of the crews of either plane escaped. The fateful accident occurred only a few hundred feet off the ground as the formation roared through thick blanket of clouds that covered the base and reduced visibility to almost zero. The density of the overcast is indicated by the fact that only a few Fortresses of the formation, which numbered more than a score, are visible in this picture. This photograph is evidence of the weather hazards that U.S. Army 8th Air Force bomber crews are forced to brave almost daily during the winter months to continue without pause their sledge-hammer blows on industrial Germany and to provide tactical bombing cooperation for our ground forces. England. U.S. Air Force Photo.'