CHICAGO (CBS) — Security guards thought there might have been an active shooter Navy Pier during Thursday night’s July Fourth celebrations, and Chicago police jumped into action in active shooter protocol only to learn there was no active shooter.

Adding to the chaos and confusion, in an apparently unrelated incident, there was a stabbing nearby around the same time.

Thirteen people were injured in the stampede, trampled on amid chaos after the fireworks show.

Chicago police say the private security guard brought in for the event urged people to take cover, leaving police to try to sort out the details.

Police did not say which private security company made the call, but said they will be in touch with the company.

“Just to ensure these things are handled properly,” said Chicago Police Supt. Eddie Johnson. “I don’t want to condemn him because he may have thought there was an active shooter.”

Only compounding the chaos was the real act of violence — the stabbing — in the same area at the same time.

Police said a young man stabbed three people during a fight near McDonald’s along the pier.

Their injuries are not life threatening, and police are still looking for two people involved.

“Unfortunately I did see a few kids get trampled,” said Tre David, who witnessed the stampede. “A little girl, she was crying, and her father came in really heroically and kind of swooped her up and just ran ooaway from the different things that was going on.”

“It felt like some sort of terror attack was going on when in reality it was just a couple people being stupid,” said witness Jacob Pawletki.

CBS 2 also asked Navy Pier for the name of the security company that called in the active shooter but did not get that answer. Navy Pier staff declined CBS 2’s interview request, but a spokesperson said, “We are still reviewing, analyzing and assessing last night’s incident and still discussing action steps and revisions to protocol internally.”

And that staff is “working with local and federal law enforcement agencies, and our private security partners to review, determine key learnings and identify opportunities to make adjustments.”

“I just don’t have details for you right now in regards to exactly what those adjustments will be,” the spokesperson said.

Crowds at Navy Pier did not appear to be slowing down Friday night ahead of Saturday’s fireworks show.

Tim McNicholas