On the evening of August 4, 2009, a mass shooting occurred at an LA Fitness health club in Collier Township, a suburb of Pittsburgh, Pennsylvania, in a strip mall known as the Great Southern Shopping Center near the borough of Bridgeville. The attack took place during a women's aerobics class at approximately 8:15 p.m., when the perpetrator entered the room, placed a duffel bag on the floor, turned off the lights, and began firing two Glock 9mm semi-automatic pistols. Police said he fired 52 shots before turning a .45 Colt revolver on himself. A third firearm, a .32-caliber semiautomatic pistol, was found on him but had not been used.
Three women died in the attack, along with the shooter. The Allegheny County Medical Examiner's office identified the victims as Heidi Overmier, 46, of Collier Township; Elizabeth Gannon, 49, of Green Tree, Pennsylvania; and Jody Billingsley, 37, of Mt. Lebanon, Pennsylvania. Nine other people were injured.
The perpetrator was identified as George Alfred Sodini, a 48-year-old systems analyst at the law firm K&L Gates who lived in Scott Township. Sodini died at the scene by suicide and was never charged, as he did not survive the attack. He had maintained an online blog in which he chronicled months of what he described as rejection by women and sexual frustration, and had referred to a planned attack as his "exit plan," stating he had previously "chickened out" of an earlier attempt. He reportedly left a note in his gym bag expressing hatred toward women. It was later reported that about a week before the shooting, Sodini had carried an inert grenade onto a Port Authority bus; he was questioned by police after a passenger alerted them, but no charges were filed at that time.
An online gun wholesaler, TGSCOM Inc. of Green Bay, Wisconsin, was reported to have sold Sodini an empty Glock 9mm magazine and a magazine-loading device used in the attack; the same company had previously sold equipment or firearms used in other mass shootings, including the 2007 Virginia Tech shooting and a 2008 shooting at Northern Illinois University. TGSCOM closed in 2012 after investigations by federal, state, and local authorities.
In the aftermath, Sodini was reported to have bequeathed his estate, valued at $225,000, to the University of Pittsburgh, his alma mater; the university said it did not wish to receive the funds and asked that they instead go to victims and their families. In March 2012, an insurance company that had issued Sodini a personal liability policy sought a legal exemption from liability, while victims alleged the insurer had failed to ensure Sodini received mental health care.
Community members, including friends of victims, women's rights advocates, clergy, and local officials, held a vigil in downtown Pittsburgh on August 6, 2009. Some feminist commentators characterized misogyny as a contributing factor in the attack, and Sodini has since been referenced in online discussions associated with the incel movement.