Originally posted by stevebrot The vapors are not safe around many plastics, and will craze some optics...just a cautionary note.
Steve
It also may discolor the black plastic, as no matter how careful you are, it goes where you don't want it to go.
With a lens of this quality, I'd send it in for repair. This crack may expand, and start letting dust, moisture in.
"It may have not been from that fall but it seems more likely since I can't think of anything else that would have caused it."
That took quite a blow to cause that much damage; so I would say definitely the fall caused it.