For all the gun owners in the thread, GarandThumb recently did a video (youtube gun guy) where he drop tested several handguns and a couple of them actually did go off. As many of you are saying, firearms shouldn't go off without the trigger being pulled and that's for sure the case a large majority of the time.

Frustratingly the article doesn't mention anything about the make, model or condition of the firearm here. It's totally possible it went off just from being dropped.