I wonder how many times friendly fire brought down bombers given how close they appear to during these raids.
More times than the US military likes to remember.
Those close formations were actually adopted for better protection against fighters. Bomber losses were heavy early in the air war, and studies showed that a significant portion of losses to fighters came from lone bombers that had strayed from formation. So they adopted those dense "bomber box" formations to maximize defensive fire, much like a herd of animals fending off predators.
Be careful what you wish for. I might let you have it.