GLEN ELLYN, Ill. Police are investigating a large disturbance in Illinois after hundreds of teens swarmed a local pool Saturday, prompting the park district to shut the facility down early.

According to police, officers were called to Sunset Pool in Glen Ellyn, Illinois, just before 5 p.m. after reports of a crowd of teens, estimated to be between 200 and 300, began to gather.

Police said many teens entered without paying, while some were reportedly smoking cannabis, drinking alcohol and setting off fireworks. Parents who were at the pool with children told affiliate WGN some teens were playing inappropriate music over loud portable speakers.

Witnesses told WGN the lines of young people waiting to get in were massive. Some individuals jumped a fence and opened a gate for others.

The overwhelming crowd and unruly behavior caused staff to close the pool early. It took several police departments to help evacuate the park, police say.

Video provided by bystanders shows the moment a pool manager was pushed into the lap pool. A young man can be seen helping her out of the water while others are seen laughing.

John Horist, who had visited the pool earlier in the day, said the situation was out of character for the quiet west suburban community.

“Glen Ellyn’s a really quiet town. I’ve been talking to the parents today and some of the kids too and they’re definitely kind of freaked out,” Horist said.

A social media post encouraged followers to “bring 31st Beach to the burbs,” telling teens to gather at Centennial Beach in nearby Naperville. Naperville police said officers were at the beach just in case, but no disturbance occurred.

It’s unclear whether the incident at Sunset Pool was related to the teen takeover planned in Naperville.

Retired Riverside Police Chief Tom Weitzel says it’s important for agencies to keep up on social media because that’s where many of the “teen takeovers” are organized.

“When it’s happening in the city, they do a really good job of moving people out, well they’re going to come out to the suburbs,” Weitzel said. “They are posting everything on either Facebook, TikTok, or Instagram, and you can see it all there. In some cases, this isn’t a surprise, but agencies just aren’t up on the social media monitoring, so maybe they’re caught off guard.”

He also said it presents a challenge for law enforcement in terms of steps they can take, forcing officers to walk a fine line.

“It’s really difficult because no police officer or agency wants to be the next YouTube video. You just can’t go in there and just arrest every single teenager and push them around and force them out, you can’t do that,” Weitzel said. “So you have to respond and smaller suburban agencies have to get cooperation from their neighbors. You do have to go in, clear it out, sometimes they’ll move on to the next location; they’ll publicize that.”

Weitzel says with an increase in these takeovers, any suburban police department that serves a community with a skatepark, pool or downtown area should prepare a response and monitor social media to get ahead of things, should one happen.

“When people are starting to get injured and there’s violence taking place, then the police do have to step it up and start to make arrests physical arrests not just citations,” Weitzel said. “You have to start to take these kids into custody because that’s a different level than just going there to post it on social media. Once it becomes violent, then police have to act differently.”

The Glen Ellyn Park District released the following statement regarding the incident:

“On July 5, due to the disruptive and unsafe behavior of several individuals at Sunset Pool, including violations of Park District ordinances, we made the decision to close the facility early. We worked closely with Glen Ellyn Police and surrounding agencies to ensure the facility was safely cleared. The safety of our patrons and staff is our top priority. We’re especially grateful to our quick-thinking Sunset Pool staff for their professionalism in handling the situation.“

One arrest was made in Glen Ellyn for illegal use of fireworks. The investigation remains ongoing.