Emergency crews were called to a fire at New Flyer Industries in Winnipeg on Thursday.
Janice Harper, vice president of human resources at the company, said the fire broke out around 5:45 a.m.
The building was evacuated and a crowd of employees filled the parking lot.
They were told to go home and come back for 9 a.m.
But late Thursday morning, they still weren't able to get back into the building.
Harper told CBC the blaze was put out by about 7:30 a.m., but smoke was still lingering in the air, no one was hurt.
Harper said company officials would make a decision by noon on whether employees would be allowed back in.
She said there were only about 20 people in the building on the midnight shift when the fire broke out.
The cause of the fire is under examination. There is no information on the extent of the damage.
The company, which makes transit buses — trolleys, electric, coaches — for North America, is headquartered in Winnipeg on Kernaghan Avenue in the Transcona neighbourhood.