I work in an emergency room and see lots of dog bites from lots of breeds. However, we’re talking one or two bites, not an attempt to kill. It seems that once certain breeds get going they won’t stop and pit bulls are the most infamous of these.
These dogs are notorious for something in them just ‘snapping’. There is some kind of trigger incident and they just loose it.
I have heard from pit bull owners here and they say there is a big hormonal component to it. A fixed pit bull is much less aggressive towards other dogs, and less likely to ‘snap’. The problem is such a singular incident cannot be predicted, or what will cause it. Once you know it’s already too late.