Originally Posted by
Canaboo
I would bet that the bolt holding a fender in place was rusted and somebody got impatient and stripped the bolt head and then used the fender as a lever to reef on it until the bolt tore out.
Could very well be. The bare metal around the tear is still rather white, so it was not all that long ago it happened. That would be consistent with a rusted bolt because of the age of the bike. It also looks like a tear more than a clean cut.