Burlington firefighters have put out a fire that erupted at a scrap metal recycling plant Thursday morning, and crews were still onsite late Thursday afternoon making sure the fire is completely out, said Acting Platoon Chief Mark Baylor.

The fire started when workers were doing some repairs on the roof that included some welding, Baylor said. The welding sparks fell on the roof, Baylor said.

"They had covered it up, but not well enough, I guess," he said. 

Once the fire started, it was hard to stop.

"You can imagine these piles and piles of scrap metal. It's just a giant warehouse full of piles of metal," Baylor said.

Crews were called to Dominion Nickel Alloys on Appleby Line just after 8:20 a.m.

When firefighters got to the facility's main warehouse the fire was too hot to even get inside, so crews set up "defensive operations" to stop the fire from spreading, Acting Platoon Chief Phil Barry said earlier Thursday.

The building was evacuated, and officials are reporting no one was injured. 

The department had 32 firefighters, multiple trucks and aerial ladders on scene at the height of the fire.