The Jefferson County Sheriff’s Office was investigating a triple shooting late Thursday night that happened following a concert at Red Rocks Amphitheatre.

Jefferson County Sheriff’s Office spokesman Mark Techmeyer said three victims were found at 6th Avenue and Kalamath Street at about 11 p.m. by Denver police. Red Rocks was shut down afterwards, with no one being allowed in or out of the park.

“We’re trying to figure out what happened,” Techmeyer said.

The Sheriff’s Office said the three victims were transported to Denver Health, adding that all were alive. Two other passengers were in the car, with the Sheriff’s Office saying they were helping with the investigation.

No arrests have been made in the shooting, which occured in a parking lot after the concert. The show featured Nas, Schoolboy Q and Flying Lotus.

Jefferson County Sheriff’s officers were searching the cars of all concertgoers. Almost two hours after the conclusion of the concert, there were still many people on the scene.

“I’m backstage; we’re on lockdown waiting to leave,” said Faithon Lucas, the promoter of the concert, which, among other causes, was a benefit for GRASP, a gang-rescue and support project sponsored by the Metro Denver Partners.

After the shooting, the victims apparently drove a vehicle into Denver. The vehicle, a white SUV, stopped at 6th Avenue and Kalamath Street, where Denver Police was called to the scene.

According to police officials, Denver Police has jurisdiction during concerts at Red Rocks unless a felony offense is involved, in which case it comes under the auspices of the Jefferson County Sheriff’s Office.

Besides the Jefferson County Sheriff’s Office and Denver Police, the Lakewood and Morrison Police Departments and the Colorado State Patrol were involved in the investigation.

The Red Rocks Visitors Center and amphitheatre were reopened Friday morning and the Skrillex show is scheduled to go on as planned Friday night, Red Rocks said on its Twitter account. The Trading Post and south parking lots remain closed while deputies investigate.

The office asks for anyone with information on the shooting to call its tip line at 303-271-5612.