The Gardiner Expressway remained closed in both directions from Yonge Street to Spadina Avenue during the Monday night commute due to fears of falling ice from the CN Tower.

The closure resulted in traffic gridlock throughout the downtown core and on routes out of the city. Some backups stretched for several kilometres.

Police said they would reassess the closure in the evening hours.

The busy downtown expressway was closed during the morning rush hour after fist-sized chunks began falling from the 553-metre structure in high wind gusts.

An officer at the scene said several pieces of ice tore loose from the tower, including one piece "four feet by four feet (and) about an inch thick." He added that the sheet of ice was carried by high winds over top of the Gardiner.

"In addition, we had some falling chunks that were irregular shapes fall on the Gardiner," the officer said.

"It is a dangerous situation if you're travelling south of the CN Tower."

Many residents arrived at work late on Monday as they tried to find alternate routes for the east-west thoroughfare.

The resulting traffic chaos meant difficult trips to the workplace.

"It has been horrendous," one pedestrian told CTV's Janice Golding. "What normally takes me 40, 45 minutes has taken me just over two hours."

It was the latest closure in Toronto's downtown due to falling ice dangers.

Last Thursday night, a freezing rain and wind storm left almost every surface in the GTA covered with a thick silvery layer of ice, including office buildings and the CN Tower.

By Friday afternoon, large chunks of ice were breaking free from buildings and crashing to the streets below. Police closed streets in a large area of the downtown core to prevent injuries and property damage from falling ice.

An area around the CN Tower was also cordoned off when huge sheets of ice were seen peeling away from the structure. That area remained closed to the public on Monday.

Officials say this is the first time since 1976 -- when the CN Tower was finished -- that the structure has seen such an ice buildup.

A busy section of King Street from York to Bay Streets was closed Monday morning due to the ice hazard. Police advised people to avoid the area.

The Gardiner will remain closed until the danger has passed, police said.

With a report from CTV's Janice Golding and files from The Canadian Press