A call of a person with a gun led to a lockdown and a scare for people working and shopping at the Westfield Old Orchard shopping center Tuesday.

At 2:33 p.m., Skokie police were called for a person with a gun near the mall. A temporary lockdown was put into place.

A business owner at Old Orchard reported receiving an alert from the mall about a person with a gun on the property. Someone who answered the phone at a hair salon at the mall reported being told to shelter in place.

From CBS News Skywatch, a line of Skokie police squad cars was seen outside the Macy's store in the mall as the events unfolded. At least eight squad cars were spotted near Macy's, and squad cars were also seen outside the Nordstrom store at the mall.

Police officers were seen walking around the perimeter with rifles as the lockdown was in progress.

"Huge rifles… kind of like standing in front of the entrance way," said Natalie Buckham.

Buckham works at the Macy's store at Old Orchard, and said she was just coming back from her lunch break when she noticed the heavy police presence.

She called a coworker from the parking garage as the mall was placed on temporary lockdown.

"And she frantically told me to stay in my car and to lock the doors, not to come inside; that they are proceeding with active shooter protocol," Buckham said.

Buckham said she hid in her car and called other coworkers who were helping get customers to safety.

"One of them was in one stock room kind of having a panic attack and crying on the phone, so I called her mother, because I am the manager," Buckham said.

Upon arrival, police determined a quarrel between two people was the cause of the security scare. Both were located and apprehended, police said.

 "Since there wasn't a shootout, you don't really get in that panic until they tell you, 'Oh, there's an active threat,'" said José Morales.

Morales said he was shopping in the Lululemon at Old Orchard when he said he and a couple dozen others were told to barricade themselves in the back.

"There were some people shaken up — you know, calling relatives, live streaming just to make sure they're all good," said Morales. "So that was the thing is like I could see the other people reacting like: 'Oh, my dad's a cop. They're letting us know that they got the person. It's all good. No shots fired.' So it was like a little bit of relief there."

Police later responded to the Old Orchard Towers medical and office buildings nearby. A source inside the towers said security told those working inside to barricade themselves in place, as security could not get over to lock down the buildings.

Once a police investigation determined there was no further threat, and no injuries or shots fired in connection with the events, the lockdown was lifted, police said.

"I think I'd want the police to respond the way they did," said Arthur Lurigio, a professor of criminal justice at Loyola University of Chicago. "You don't know what's going to happen."

Lurigio said police are obligated to be hypervigilant, and not to take chances. He said that was why there was such a massive police response outside the Macy's and Nordstrom stores at Old Orchard Tuesday afternoon.

He compared it to the response to Monday night's shooting inside an office building in Midtown Manhattan in New York City, which left an NYPD officer and three other people dead.

"Yesterday's example is New York is what we can come to expect moving forward, is that we're going to get a pretty strong response to these kinds of calls," Lurigio said.

After shoppers and workers were told the lockdown was lifted and they could go back, Buckham said the rest of the day, the mental toll of what everyone went through made it difficult to carry on.

"Back at work, clocking in, making sales — that's kind of the way of the world," she said. "But do I agree with that? No, I don't. Wholeheartedly, I don't." (17:19:50)

Skokie police said they were still investigating late Tuesday night. CBS News Chicago asked if a gun was ever recovered, and Skokie police responded only that the investigation is active.

Anyone with information should call Skokie police at 847-982-5900.

• Skokie