After a little bit of research, that B-17 in the first couple of pictures posted by DMViagra, the damage wasn't a result of a flak burst. It was from a collision with an enemy plane.
The B-17 was named "All American" and flew with the 414th Squadron, 97BG and piloted by Lieutenant Kenneth R. Bragg.Same photo as #2 in DMViagra's post but from a slightly different angle
A picture of All American in flight.
Another shot of it on the ground
One more picture showing the damage to the left side.
The other B-17 seems to be this B-17 that took a direct hit over Debrecen, Hungary, killing or wounding close to half the crew but made it back to England where it broke apart on landing.