Toronto's downtown core was a little bit hazier than usual today for a brief period thanks to a smoking school bus on the Gardiner Expressway.

The vehicle was filled with children, according to Toronto Fire Services, when downtown condo residents spotted it driving slowly along the highway followed by a plume of thick, grey smoke.

Firefighters were quick on the uptake: By the time the bus had hit the stretch between Strachan and Jameson Avenues, two trucks were following it with their sirens blaring.

A smoking school bus filled with children was evacuated today on Toronto's Gardiner Expressway. 📽️: Ildikó Éder pic.twitter.com/Fgz4KPuy7l

— blogTO (@blogTO) August 7, 2019

A local who observed the mess posted video footage to a popular community Facebook page around 9 a.m., noting that "there were kids on the bus, but they are fine."

After they were rescued by firefighters, the children are said to have stood along the highway after, supervised by emergency responders, until another bus was sent to pick them up. Meanwhile, a portion of the westbound Gardiner closed down.

Despite all the smoke, officials say they didn't find any fire on board. Whatever caused the plume, all involved are grateful that everyone managed to make it off the bus unharmed.. save, perhaps, for angry commuters who were held up by the incident during this morning's rush hour.