I remember being at the "cottage" [[was a shack and not near a beach) watching heavy National Guard vehicles [[someone here said there were no tanks used) rumble up Grand River and wondering how the tunnel fared. It was a snowy black and white picture, no pixellation, though. Never shopped there again so I don't know the answer.

Another tunnel I know of is under Lafayette. It connected the Detroit News with WWJ TV and radio. It was filled in/blocked off when the News sold off WWJ.