John Coligan, a 31-year-old male, was killed on March 16, 1985, during a workplace shooting at the Anchor Glass Container Corp. plant in South Connellsville, Pennsylvania. The violence erupted on what had been an ordinary Saturday morning inside the glass plant, a place where foremen and workers were going about their shifts when a recently disciplined employee returned with a gun and turned the workplace into a scene of panic and death.
The gunman was identified in contemporary and later reporting as Mansel “Sonny” Hammett, a 39-year-old Anchor Glass employee from Dunbar, Pennsylvania. Earlier that morning, Hammett had been sent home after a disciplinary issue. Accounts differ slightly on the exact timing, with some reports saying he returned roughly around 10 a.m. and others describing a longer gap after he was sent away, but the sequence is consistent: after leaving the plant, Hammett came back armed with a. 38-caliber revolver.
When Hammett returned, he first encountered security guard James Silbaugh and struck him in the head with the revolver. He then entered the plant and began seeking out supervisory employees. John Coligan was one of four men killed in the attack, along with Donald Abbott, Paul Gabelt, and Ralph Tomaro. Richard Hosier was also shot and seriously wounded but survived. Later accounts from South Connellsville officials described Hammett as having targeted supervisors, and one recollection stated that Coligan and Tomaro were in a small office, having coffee at their desks, when Hammett entered and shot them.
Witnesses and investigators described the attack as sudden and devastating. Hammett moved through the plant firing at managers and foremen, while workers fled or hid from the gunfire. One later account said Hammett had reportedly gone to the cafeteria at Pechin Shopping Village before returning to the plant and told people there that he was going back to Anchor Glass to kill bosses. Former South Connellsville Police Chief Pete Casini, who responded to the scene, later recalled the day as the worst of his career and described finding Hammett’s body inside the plant after the shootings.
There were no arrests, charges, trial, or conviction in John Coligan’s death because the suspect did not survive the incident. Police and coroner accounts identified Hammett as the lone gunman, and one officer was quoted as saying Hammett did all the shooting and that nobody else fired a shot. After killing four supervisors and wounding Hosier, Hammett turned the gun on himself and died by suicide at the plant.
The aftermath left the small Fayette County community shaken. The victims were remembered not as statistics but as working men killed in a place where they should have been safe. For John Coligan, the final moments came amid a broader workplace massacre driven by anger over discipline, pressure, and conflict at the plant. Because Hammett died at the scene, the criminal case ended there, with the official focus falling on the confirmed suspect’s actions rather than on prosecution.
