O.K. Corral Gunfight

On the cold afternoon of October 26, 1881, four men in long black coats strode purposefully down the dusty Fremont Street. Around the corner, in a narrow vacant lot behind the O.K. Corral, waited six cowboys. In a fateful thirty seconds, nearly thirty shots were fired at close range.
A failed plot actually triggered the shootout.
Unfortunately, the three men were killed before Clanton could name names. Clanton became paranoid that the plot would be discovered and he'd be labeled as a rat - that was the real trigger for the shootout