There was an explosion and fire at the Nova Forge building in Trenton, N.S., but no one was badly hurt.
Witnesses described hearing a loud noise before seeing flames Tuesday morning.
"I heard a big bang and a pop, pop, pop," said Joan Krawczyk, an artist at nearby Trenton Art Works.
Krawczyk opened the blinds and saw smoke billowing from the building across the street. She gathered with neighbours at a nearby park and watched the fire spread.
"One fellow said that he was at the top of the hill and he saw the flames shoot straight through the roof," Krawczyk said.
Police said the first call for help came from Nova Forge employees.
Const. Ken MacDonald, spokesman for the New Glasgow police force, said all workers were accounted for and no one was seriously injured.
Firefighters from three departments were called to battle the blaze.
"Every now and then there's a big puff of smoke. The roof is collapsing," said Krawczyk.
The DSTN wind turbine factory is on the same property as Nova Forge, but it wasn't damaged in the fire.