Sources say purported hostage situation that put Northwestern Memorial Hospital on lockdown was a hoax; not clear if it was a swatting incident

CHICAGO (CBS) -- On Sunday night, police rushed to Northwestern Memorial Hospital with a SWAT team and put one of Chicago's biggest hospitals on lockdown for hours.

As CBS 2's Marissa Perlman reported Monday, a high-ranking source says it was all a hoax. But Chicago Police were not confirming that report Monday afternoon.

Meanwhile, for hours on the cardiology floor, one patient said she was left in the dark.

The call came in on police scanner audio claiming there was a man with a gun holding a nurse hostage in an elevator at the Streeterville medical center. It was from a man who claimed he was upset about being overcharged.

An officer is heard saying in a dispatch report, "We're probably going to have to make this a SWAT incident."

SWAT teams rushed inside, clearing the hospital as it went on lockdown Sunday night. On the cardiology floor was Harrie Kevill-Davies, who has advanced heart failure and was getting fluid drained from her lungs.

"I heard this announcement over the PA system saying: 'Intruder alert! Armed intruder alert!'" Kevill-Davies said. "Something like, 'Pre-brace and find shelter.'"

Video posted from another patient shows the view from another hospital room. A huge police presence was seen, and the entire perimeter of the hospital was roped off.

Nurses came in to lock patients' doors and turn off the lights. The nurses were told to hide.

"I saw one of the nurses kind of bolting down the double doors," Kevill-Davies said. "The nurses on my unit were huddled in a shelter room together."

But just a few hours into the intruder announcement, Chicago Police lifted the lockdown and found no threat.

Police sources, again, say it was a hoax. It is unclear whether this was a swatting situation – when someone makes a prank call to emergency services to bring a large number of armed officers to one location.

Swatting is a federal crime carrying up to five years in prison.

"I don't understand how this can be a prank or a practical joke," said Kevill-Davies. "It's far from funny."  

If this does turn out to be a swatting situation, it would be the second that Kevill-Davies – a student at Northwestern University – has experienced.

"There were snipers on the roofs of some of these buildings and stuff like that," she said.

Kevill-Davies was on campus in 2018 when Evanston police, students, and staff at Northwestern were led to believe there was an active shooter on campus. Police later determined the 911 calls and reports were a hoax – after a massive lockdown and police response.

CBS 2's Perlman asked Evanston police Cmdr. Ryan Glew why somebody would stage a swatting.

"To cause chaos on some type of scale," Glew said. "Sometimes it can be directed at an individual, or it can be directed at an institution."

Cmdr. Glew said the suspected caller was never found, but he emphasized that making that swatting call was a felony. Not only does it stress the community at large, but it can take resources from other incidents that do need an emergency response.

"The ability to provide other services to the community can be greatly diminished, and almost impossible, to provide during that time," Glew said.

Neither Chicago Police nor Northwestern Medicine has confirmed this was a swatting incident. But they also said at this point, no one is in custody.

Now, the question is not only who was behind the reported hoax, but at what cost.

In:
• Northwestern Memorial Hospital
• Streeterville
• Chicago Police Department