A mass shooting at a New Jersey arts festival left 22 injured and 1 dead.

Early Sunday morning, the 12th edition of the Art All Night festival in Trenton, New Jersey, was shook by a mass shooting that left 22 injured—17 shot, the others hurt during a manic stampede—and 1 dead. The shooting, authorities told the New York Times, was not a targeted assault on the arts space, and was instead confirmed as an attack motivated by a gang conflict.

The annual arts festival advertised on banners that it would offer “24 hours of creativity, community & inspiration,” and was expected to host more than 25,000 attendees over the course of the program. At the moment of the shooting, about 1,000 people were in attendance. But attendees reported that tensions had been gradually rising between people affiliated with different gangs, and at one point, Trenton police received a screenshot of a Facebook post that read, “Please. Please. Please. Do Not Go to the Art All Night. They will be shooting it up.” But before any preventative action could be put into effect, gunfire broke out just shy of 3:00 a.m., turning the arts festival into a sea of chaos that caused a dangerous melee of people trying to escape the carnage.

Two of the suspects were critically injured and are now under police guard in the hospital. Police fatally shot Tahaij Wells, a gang member who was active in the shooting, on site; Wells was recently released from prison for a fatal shooting he committed in 2002, when he was 17.

Four hours after the shooting, Art All Night announced on its Facebook page that it was  canceling the remainder of the event, which was supposed to continue until 3:00 p.m. Sunday. The group closed their message by stating: