They were 2 friends at a Prosser birthday party. Now 1 is dead, the other in jail.

An argument between two friends at a birthday party turned violent early Saturday morning, ending with the death of a woman in Prosser.

Amy S. Brown, 36, and her 35-year-old friend were celebrating the birthday of the younger woman’s boyfriend at a home on North River Road when the dispute started, Benton County Sheriff Jerry Hatcher said.

It’s unclear what prompted the fight between the two, whom Hatcher described as “best friends,” but Brown allegedly got a pistol and shot her friend in the chest at 12:45 a.m.

Several people called 911 after they heard the gunshot. When deputies and Prosser police arrived minutes later, they found Brown holding her dying friend, who had stopped breathing.

Officers and deputies couldn’t find a pulse, and despite efforts from police and medics, the woman died at the scene.

Brown is being held on an investigative hold for second-degree murder and first-degree manslaughter.

An autopsy is scheduled for later this week.