On the morning of August 3, 2010, Omar Sheriff Thornton, a 34-year-old employee of Hartford Distributors, a beer and wine wholesale distribution company in Manchester, Connecticut, was called into a disciplinary meeting. Thornton had previously been recorded by a private investigator stealing beer and was implicated in the theft of empty beer kegs. During the meeting with general manager Steven Hollander, supervisor Louis Felder, and union representative Bryan Cirigliano, Thornton was shown video evidence of the theft and given the choice to resign or be fired. He chose to resign and was escorted from the building.
While being escorted out, Thornton asked to get water in the kitchen. There, he retrieved a Ruger SR9 handgun from a lunchbox he had carried into work that day and opened fire. He killed Louis Felder and grazed Steven Hollander before fatally shooting Bryan Cirigliano in a hallway. Thornton then moved into the warehouse, where he shot and killed Douglas Scruton, Victor James, and Craig Pepin. He pursued and killed Francis Fazio and William Ackerman near a trash compactor area. He shot Edwin Kennison in the shoulder, chased him outside, shot Jerome Rosenstein three times as Rosenstein drove past on a golf cart, and then fatally shot Kennison after he fell and pleaded with him. Thornton spared one female coworker, citing her multiple sclerosis, before retreating into an office as police arrived.
In total, eight men were killed and two others were wounded within a span of a few minutes. Police arrived three minutes after the first 911 call and entered the building ten minutes later. Thornton locked himself in an office, called his mother to tell her what he had done, and then called 911, telling the operator that his motive was racism he said he experienced at work, and stating he wished he had killed more people. Shortly after telling police he was coming out, he killed himself with a gunshot to the head. Investigators determined he had fired 26 rounds, including the fatal shot to himself, reloading only once.
Family members and Thornton's girlfriend later said he had complained of racial discrimination at work, including an alleged image of a noose and a racial slur in a bathroom. Company officials, union representatives, and other workers denied these claims, and a police investigation did not find evidence supporting the allegation of racism at the company. The shooting is described as the deadliest workplace shooting in Connecticut history and the third-deadliest mass shooting in the state's history. Separately, two individuals were arrested in connection with receiving property allegedly stolen by Thornton; one was later arrested again after an incident involving reporters.