An alarming video of a woman tossing a chair off the balcony of a downtown Toronto highrise, toward the Gardiner Expressway below, is now the subject of a criminal investigation.

Toronto police confirm the cybercrime unit is looking into the video, which began circulating online over the weekend.

The short, nine-second video was taken from “a very high floor” of a building near the Gardiner, at Harbour and York streets. In it, a woman stands on a condo balcony and lobs a small chair over the railing and onto the highway below.

The video ends before the chair hits the ground. Police believe it was flung from 20 to 30 storeys up.

“Outrageous, that’s what I would say,” Toronto police spokesperson David Hopkinson said of the video.

“I’ve seen a lot of things in my police career but the absolute propensity for this to be very violent, to be very dangerous is easily there. We’re talking 30 floors up, a metal chair, in front of a condo building… Anybody could be walking under it.”

Police said multiple items were thrown off the balcony on Saturday morning, at about 10 a.m., when the video was taken. The chair and other items reportedly landed at the front entrance of another condo building in the area.

“It landed on the sidewalk in front of the building,” Hopkinson said. “We have recovered the chair. It was still on the sidewalk, damaged almost beyond recognition.”

There was no word from police on whether any vehicles were damaged or if anyone was injured.

Investigators are looking at whether the condo unit was being rented out at the time of the incident.

The young woman in the video has not yet been identified.

“Some of these buildings are not only condominium buildings, they’re hotels. Some people rent their homes out for the weekend. So that is part of the investigation -- that we would seek information from the concierge or from security or management -- but it won’t only involve that,” he said.

“We’re putting out the picture of this woman in hopes that someone would be able to identify her so that we can further our investigation.”

She has been described as being in her 20s, approximately five-foot-one to five-foot-two, 110 pounds with a slim build and long blonde hair. In the video, she was wearing a black leather jacket, black clothing and black high heels.

Police are currently investigating the incident as a “mischief investigation, endangering life.”

“Anytime you do something that endangers the life of others, particularly in the public, that warrants a criminal investigation,” said former Toronto police detective and CP24 crime specialist Steve Ryan.

“Whether or not that was her intention when she threw that chair over the balcony, she ought to have known that if that chair would’ve hit somebody, she could’ve caused damage or death.”

Anyone who recognizes the woman in the photograph provided by police is being asked to contact them or Crime Stoppers anonymously.