Fluegelman was the editoral director of both PC World and Mac World magazines in the mid-1980s. He was also the author of the communications program PC-Talk III. Fluegelman owned the copyright to the term "freeware," which was not enforced after his disappearance.

Fluegelman departed from his family's residence in Marin County, California during the morning hours of July 6, 1985. He arrived at his office in Tiburon, California shortly thereafter. He called his wife from his office during the afternoon. Fluegelman has never been heard from again. A week after his disappearance, his 1982 Mazda was found parked near the toll plaza on the Marin County side of the Golden Gate Bridge. Investigators believe Fluegelman jumped off the bridge; a suicide note was found in the vehicle. His friends and family say he was acting oddly in the days before his disappearance.

Fluegelman's family held a memorial service for him in New York shortly after he vanished. He is presumed to have taken his own life, but his remains never been located.