I don't know why Zorin worked. Other distros warned that the file system was in a dangerous state, no doubt from the system crash. So either Zorin was smarter or too dumb to notice, I don't know. (And yes, of course it's a Linux Ubuntu distro; my post wasn't clear.)

I'll check out SystemRescueCD. This sort of thing seems to land on my desk on occasion. One more tool in my toolbox.