Question for Sweet Comfort Fans

I hope this doesn't offend anyone. I have a question, and I get the impression that this is a sensitive topic, since I can't get an answer from anyone. And nothing comes up in a google search. Probably some time in the early '90s, Kevin Thomson had a back injury that paralyzed him. No one ever says what the injury was. I just find it very strange that no one explains what happened, and I find it hard to believe that such an accident could be somehow 'personal.'

Does anyone know how Kevin injured his back? If he fell off the roof of his house, do you know what he was doing? Roof repairs? Why would this be 'sensitive,' and secret?