I lost track of one of my old elementary thru high school friends. He went to school for training to be a cinematographer and drifted away from everyone else I knew. Last time I saw him was 1980.
We did some research and found out he ended up homeless, living in a box under a bridge on the upper west side of Manhattan. He was then stabbed to death by some rando nutcase, for the hell of it.
Knowing him, I knew it had to be some drug or another. His death came in '94, so I figure he must have gotten addicted to crack. He was on the street for a few years. It's really weird to find out stuff like this, decades after the fact.
Some additional detail -- about a year before he was killed, his mother died and he was left $10K in an insurance policy. He partied like a maniac for a month, then was back on the street.