A huge outdoor party in Williston, Fla., erupted in violence on Saturday, leaving five attendees shot and one 36-year-old man dead, local police said in a statement.

Police have arrested Devonte Tremaine Ocasio, 19, in connection with the shooting spree at “Crabfest,” an annual street festival that draws thousands of revelers to Williston, a city of less than 3,000 in northeastern Florida. Despite its name, the event is actually a giant, unsanctioned street party, and this year it drew about 10,000 people, the Sun-Sentinel reports. Ocasio has been charged with attempted first degree murder, discharge of a firearm with injury, aggravated assault with a firearm, and possession of a firearm, local television station WCBJ ABC News-20 reports. He is being held on $1.5 million bond.

“While it is called the Crab Festival, it is actually a series of 'Hip Hop'-style street parties,” the Levy County Sheriff’s Office said in a statement, noting that the event has been the scene of violence in the past. “The vendors, large crowds and numbers of vehicles force the closing of many roads, including County Road 318.”

Crabfest has no corporate or government sponsors, relying solely on social media and word of mouth for promotion, The Sun-Sentinel reports.

Saturday’s violence occurred despite extensive efforts by police to ensure the welfare of Crabfest’s participants.

“The Levy County Department of Public Safety had pre-staged ambulances and a Medical helicopter in the area for the festival. The large crowds made it impossible for ambulances to reach the wounded,” the statement added. “Despite the large crowds walking and dancing in the roadway, deputies and EMS personnel were able to evacuate the victims in law enforcement and private vehicles.

The Levy County Sheriff's Office is following leads regarding a possible second shooter.