In February of 1983,  a plumber was called to clear the drains of a small apartment building in London, UK.  Though the plumber would discover the drains were clogged with human remains, this would unravel the mysterious disappearances of 16 men. This is the story of Dennis Nilson.

Sources:
Caught By Flushing Body Parts Down The Toilet, World’s Most Evil Killers, Real Crime, December 22, 2020, Caught By Flushing Body Parts Down The Toilet. Youtube.com

The conviction of serial killer, Dennis Nilsen, The Nilsen Files, BBC, February 4th, 2022. Video. Youtube.com

How A Serial Killer Was Caught By A Plumber's Gruesome Discovery, Memories of a Murderer, Still Watching Netflix, August 18th, 2021.Video. Youtube.com