A 24-hour festival in Trenton, New Jersey, was abruptly cancelled when shooting erupted early Sunday morning. At the annual event Art All Night, gunfire inside and outside the building between multiple people resulted in one suspect being shot dead. The violence appears to have been caused by a gang-related dispute.

Twenty two people were injured in the shooting that started around 3 am, when around 1,000 people were attending the overnight community arts event, whichIt included a variety of performances, interactive art, music, and an art market. The festival organizers had been trying to close down the event after fights had broken out, but people continued to loiter. While the motive for the shooting is under investigation, authorities say it was likely gang-related.

“We believe it was a dispute between two neighborhoods that led to violence at the event,” Mercer County Prosecutor Angelo Onofri told ABC News. “In no way was the event the target, it just happened to be the forum for the shooting.”

“We’re very shocked. We’re deeply saddened,” the festival organizers wrote on social media. “Our hearts ache and our eyes are blurry but our dedication and resolve to building a better Trenton through community, creativity and inspiration will never fade. Not tonight. Not ever.”

The dead gunman has since been identified as 32-year-old Tahaji Wells, an alleged gang member who was known to the local police. Authorities also believe that he was shot dead by police fire. One 13-year-old boy was in critical condition, but has since been stabilized.

Another suspect, 23-year-old Amir Armstrong, has been charged with possession of weapons, and another unidentified suspect is still in the hospital.

“We’re still trying ourselves to piece this entire situation together,” wrote the festival organizers on their Facebook page. “What we do know is that we are currently unable to release any submitted artwork that is currently inside the Roebling Wire Works building.

The 12-year-old art-and-culture festival ran from the Saturday afternoon to Sunday afternoon this weekend in Trenton. The weekend event takes places annually in the historic Roebling Wire Works building and has been well-loved for helping to revitalize the arts scene in a city that has struggled with poverty, drugs, and violence for years.