On the morning of Thursday, February 14, St. Valentine's Day, six members of George 'Bugs' Moran's gang and a doctor who happened to be at the scene were lined up against the rear inside wall of the garage of the S-M-C Cartage Company in the Lincoln Park neighborhood of Chicago's North Side.
They were then shot and killed by five members of Al Capone's gang (two of whom were dressed as police officers).
When one of the dying men, Frank "Tight Lips" Gusenberg, was asked who shot him, he replied, "Nobody shot me." Capone himself had arranged to be on vacation in Florida at the time.

Roger Corman was given the huge budget (for him) of one million dollars by 20th Century Fox to produce this documentary-esque depiction of the infamous 1929 shooting of seven Chicago mobsters.
It's a fascinating reproduction of a time when bloodshed was plotted in business boardrooms and tommy guns were a daily fact of urban living.

Jason Robards stars as mob boss Al Capone, with Ralph Meeker as his North Side rival Bugsy Moran.
George Segal is Peter Gusenberg, one of Bugsy's henchmen targeted for takedown.
To add a little sex and spice, there's a lengthy domestic-dispute scene between Gusenberg and his lovely negligee-clad moll (Jean Hale).

The rest is strictly business and bullets though, with Robards chewing the scenery to nice little splinters and lots of Corman regulars appearing in bit parts, including Barboura Morris and Dick Miller. Bruce Dern appears as a getaway driver.
One has to keep a sharp watch to find Jack Nicholson, who floats through several scenes as one of Capone's assassins. It's a fast-moving, well-told saga, with excellent period reproduction thanks to sets refurbished from MY FAIR LADY and great deadpan narration by Paul Frees.