For those that haven't seen it yet - over on the PostNuke Website, there is a note about the passing Greg Allan. Greg Allan a.k.a. Adam_Baum, the lead core developer and one of the four founding members of the PostNuke CMS Development Project passed away from injuries sustained in a motorcycle accident. The accident occurred June 16, 2002 near his home in Meaford, Ontario in Canada.

There are some notes about the funeral and more information about this very influental developer who was one of the key players in bringing PostNuke into the world. One of the other developers, Florin Racolta, attended the funeral and wrote some of the comments said there.
Not only has the PostNuke project lost a developer, but a dear friend to a lot of people out there.
(Note: I realize that this happening is a bit old, but it is still very much worth mentioning.)