By Trang Do

PHILADELPHIA (CBS) – Four police cars were damaged after hundreds of teens and young adults assembled in North Philadelphia Sunday night.  The police department put out a citywide assist call for all available officers just before 11:30 p.m. for reports of a massive crowd of young people gathered near the intersection of N. Sydenham and W. Jefferson Streets.

“Anywhere from 800 to 1,000. There were a lot of young adults out here tonight,” said Chief Inspector Joel Dales.

Before officers arrived, neighbors described mayhem. Rachel Williams watched helplessly as a dozen teens climbed onto her car.

“Twelve kids were like dancing and twerking and going insane on top of my car, as well as just everywhere,” she said.

A man named Aaron who was there said it started out as a regular cookout right around 5 or 6 p.m., but that things escalated by nightfall when several people shared the location on Snapchat.

“They had a tent with a DJ popped up and everything like that. They had alcohol, jungle juice going up, but honestly, obviously, I didn’t set it up but there was a lot of really, really young children here that probably shouldn’t have been messing around with any of this,” said Aaron, who withheld his last name.

Police say members of the group damaged four patrol cars, bashing in hoods, busting windshields and breaking off side mirrors.

“We had no information whatsoever giving us a warning being that these kids were going to gather out here,” Dales said.

Investigators later learned the gathering started out as a cookout. A message went out on Instagram about a “free party,” which brought hundreds of young people to the area.

Despite some chaotic moments, Dales said officers got a handle on the situation quickly.

“The officers did a great job responding, they got the situation under control quickly and again they were able to protect the businesses and no injuries to adults nor injuries to the young adults,” he said.

Police did not make any arrests, though investigators are looking for surveillance video in hopes of identifying those responsible for vandalizing the patrol cars.