Heavy black smoke filled the sky in Port Colborne, Ont. as a massive fire burned at a vinyl products factory on Tuesday morning.

Fire crews battled the blaze at the Vinyl Works Canada facility. Smoke could be seen for several kilometres. By Tuesday afternoon, the fire was under control but fire crews were still tackling some hot spots.  

Deputy Fire Chief Mike Bendia said he was surprised by how quickly flames tore through the industrial building, which has fully collapsed. He said about 55 firefighters from multiple departments will likely continue their efforts into Wednesday morning.

No injuries have been reported. Bendia said it is too early to comment on potential causes.

The fire was reported at 7:40 a.m. Bendia said crews faced multiple “small explosions,” likely from propane tanks, upon arrival at the factory on Barber Road. The building began to collapse as crews set up equipment.

Niagara Regional Police have blocked two roads near the industrial park where the building is located, and have advised people to avoid the area.

Niagara Region officials encouraged those in the vicinity to stay inside and close all windows and doors. The Ministry of the Environment is monitoring local air quality.

Air samples taken in the nearby town of Fort Erie have tested negative for toxic chemicals, officials wrote in a tweet.