In New York City in 1933, during both the Great Depression and the Prohibition Era, a group of guys - Tony Marino, Daniel Kriesberg, Francis Pasqua, and Joseph Murphy - hatched a plot to kill Michael Malloy, a regular at the speakeasy that Marino owned, and collect on a few insurance policies that they were going to take out on him. After several failed attempts, they enlisted the help of Tough Tony Bastone and his sidekick Joseph Maglione, and later one even cab driver Harry Green and local doctor, Dr. Frank Manzella. It would seem that it was impossible to kill Iron Mike, as he came to be known.

Sources for this episode:
Wikipedia - New York City
all that's interesting - The Curious Case of Michael Malloy - "Rasputin Of The Bronx"
Smithsonian Magazine - The Man Who Wouldn't Die
Drinking Cup - The legend of Mike Malloy and the Murder Trust
Trivia Library - New York Gangs Murder Trust and Michael Malloy Parts 1-5
Irish Central - Michael Malloy - the Irishman in The Bronx that could not be murdered
The True Crime Edition - The Murder Plot of "Iron" Mike MalloySupport the show