Colleen Wies Fantozzi let me know that Mark passed several years ago.  In April, 2010 we received an email from Mark's cousin, Ed Durbin that read as follows:

I came across your site and saw that a member had asked how Mark passed. He committed suicide, I was his cousin. I thought maybe you'd like to add how he passed to the site so people would know. As for having any details, there are none, his part of the family was very distant from the rest of us, and we weren't invited to a funeral or given any obituary details. He committed suicide in his garage December 10 2007 and was cremated, that's about all the info we have.

Ed