GURNEE, Ill.  — Three people were shot in the parking lot of Six Flags Great America in Gurnee, prompting a heavy police presence Sunday night.

A 17-year-old boy from Aurora, Illinois, had a thigh wound and a 19-year-old woman from Appleton, Wisconsin, had a leg wound, police said. They were taken to a hospital and their wounds were described as non-life-threatening. A third victim had a shoulder injury and declined to be taken to a hospital.

No one is in custody.

The amusement park, which closes at 8 p.m., was evacuated.

A Six Flags spokesperson confirmed the shooting, issuing the following statement:

Three people were injured this evening when shots were fired from a single vehicle in the parking lot. The vehicle immediately drove away. Park security personnel and officers from the on-site Gurnee Police Department Substation responded immediately. Emergency services responded, transporting two persons to the hospital for evaluation. A third person declined treatment.

The park closed early with guests and team members departing under direction of the Gurnee Police Department. Law enforcement is investigating.

WGN News spoke with Laurie Walker and her daughter, Grace, who were inside the park when the shooting incident occurred. Walker said they were waiting in line for the ‘Ricochet’ in the southwest area of the park around 7:50 p.m. when she noticed people running in a panic.

“There is an active shooter, get down, get down,” Walker recalled someone shouting. “We didn’t know what was going on, so we get down.”

VIDEO: Mother recounts moments shots rang at Six Flags Great America

Walker and her daughter climbed over two fences to get “out of plain view sight,” where she could call her husband. After hiding out for a short while, Walker says she was able to leave the park.

Authorities told WGN News that law enforcement officials are actively searching the area to ensure everyone is located and accounted for. 

This is a developing story. Stay with WGN News for updates.