PITTSBURGH — Kennywood Park remained closed Sunday after three people were injured in a shooting and others suffered what Allegheny County police described as “trample injuries” in their scramble to escape the chaos during the Saturday night opening of the park’s Phantom Fall Fest.

Shots rang out in front of the Musik Express ride near the Lost Kennywood area of the park about 10:50 p.m., the result of “an altercation” between two groups of young men, county police Superintendent Christopher Kearns said. During the fight, at least one person pulled out a gun, and two shots were fired, Kearns said.

A 15-year-old boy was shot in the leg and was being treated at UPMC Children’s Hospital of Pittsburgh. He was listed in stable condition, according to county police.

A 39-year-old man also was shot in the leg and was treated and released from UPMC Mercy.

Police said a second 15-year-old boy was grazed by a bullet in his leg but left the scene and later arrived at UPMC McKeesport. He also was listed in stable condition.

Kearns said investigators were searching for a young Black man in connection with the shooting. He was wearing a black hoodie and a black medical mask, police said.

Austin Mathew and his fiancee, Nikki Miller, of Butler were among Kennywood guests on their way out Saturday night when the shots rang out.

Miller, her sister and her sister’s boyfriend decided to jump on the Cosmic Chaos on their way out because the line was short, but Mathew stayed behind.

“Right before the ride started, that’s when we heard the gunshots,” Miller said. “We start running and then the gate to get out of the ride was locked and there were parents trying to get the gate open and there were so many little kids. We all had to jump over it.”

Mathew was nearby outside the ride but had to try to find Miller and the others through the chaos.

“I had to run at the people running to me to try and find Nikki,” Mathew said.

The sound of the gunfire was very close to where they were at the time said Miller, who guessed they were 30 feet from the initial shots.

“We knew we were so close, but we didn’t know if we running in the direction the guy is going to be,” Miller said. “You just knew you are in proximity.”

Once everyone in their party was accounted for, Mathew and Miller started making their way towards the main entrance tunnel for their escape.

“It was so crowded, there were people getting trampled,” Miller said.

County police spokesman Venerando Costa said Sunday morning that police found a handgun near the scene of the shootings.

Costa said no more information was expected to be released Sunday about the incident.

“We are greatly saddened by the violence that occurred last night. Our thoughts are with those who were injured as a result of the incident, as well as all guests and team members affected by what happened,” Kennywood’s general manager, Mark Pauls, said in a statement Sunday.

Pauls said Kennywood increased its security this season with new protocols, including a state-of-the-art weapons detection system, as well as video scanning and bag checks.

“We regularly supplement our park security staff with officers from the Allegheny County Police Department and West Mifflin Police Department, who were contracted to support our teams during operating hours, including Saturday evening,” he added.

The statement added that Kennywood has made services available for team members in need of mental health support.

Metal detectors were being used to scan people as they entered the park Saturday night; police said they did not know how the shooter got his weapon through that security.

Five county police officers, two West Mifflin officers and Kennywood’s in-house security were patrolling the park Saturday night, police said.

West Mifflin police Chief Greg McCulloch said his officers helped one of the shooting victims and called for backup to assist with the others. He also said his officers helped to escort guests out of the park.

Reports of the shootings resulted in a massive police turnout, with officers arriving at the sprawling amusement park from many departments countywide.

County police initially said there was "an incident" at the park. A later tweet from the Pittsburgh Public Safety Department said city officers were assisting in response to shots fired.

People inside the park described a scene of chaos as parents and children rushed for exits as word spread about the gunfire.

About 12:40 a.m., police said everyone inside the park had been evacuated, with just a few outside waiting for rides out of the area.

Kennywood workers exiting the park said they had been told not to talk to reporters about the incident.

Kennywood's annual Phantom Fall Fest, a popular event that draws large crowds to the amusement park, began this weekend.

Early Sunday, police officers could be seen in front of the Musik Express ride, where incident tape had been strung, evidence markers had been placed and a pair of sunglasses lay on the ground.

At about 12:30 a.m. Sunday, Kennywood communication manager Tasha Pokrzywa released this statement:

“The park is closed for the night and all guests have exited. We are aware of a situation that occurred this evening and are working with local law enforcement. The safety of our guests and team members are our top priority. Members of the park's security, Allegheny County, and West Mifflin police departments were already on site and immediately responded.”

Most of the responding officers and emergency crews had left the area by about 1:30 a.m., and police said they were letting employees back into the park a few at a time to gather their personal belongings.

As the investigation inside the park progressed, Valerie Franklin, of Duquesne, waited for her 19-year-old son, Brandon, at the main gate. She said he had just recently started working at Kennywood.

Franklin said she was listening to her police scanner about 11 p.m. Saturday when she heard a call about a person in the park with a gun.

“I was panicked and called him right away,” she said, adding that Brandon answered the phone and told her he had heard gunshots and saw people running.

”I pray for the kids and the people transported,” Franklin added.

Ward Troetschel, of West Mifflin, said he arrived at Kennywood about 9:45 p.m. for the Phantom Fall Fest. At the time, he said, he saw “way too many unaccompanied minors.”

He said he left the park about 10:30 p.m. because young people were aggressive and “were trying to start fights.”

As he left, he said, people in groups of at least 100 ran past him two or three times.

Troetschel said the scene had “lots of chaos.”