Two people were hospitalized with burn injuries after a magnesium fire erupted at Coogee Chemical Plant in Ottawa on Tuesday morning, Ottawa Fire Chief Brian Bressner said.

Firefighters were dispatched a little before 8 a.m. to the plant in the 1500 block of Titanium Drive. Upon arrival, firefighters witnessed white smoke coming from the building and confirmed it was a magnesium fire, Bressner said.

One person is in critical condition, he said. The condition of the second person is unknown at this time.

Five employees were working in the building at the time of the fire. The other three did not sustain injuries and helped their coworkers until firefighters arrived, Bressner said.

“The fire was contained pretty quickly,” Bressner said. U.S. 6 was shut down temporarily, and a shelter-in-place order was issued for nearby manufacturing facilities. The order was lifted about 45 minutes after firefighters arrived, once the fire was contained.

Bressner said there was no danger to the public.

“The smoke coming off was contained on-site. The smoke didn’t have hazardous chemicals,” Bressner said.

The fire started when facility workers were moving magnesium powder from one container to another, Bressner said. The facility uses argon gas to help control the powder. A problem with either the argon or too much oxygen in the container allowed the magnesium to oxidize and ignite the fire, he said.

“Once magnesium starts on fire, it does explode,” he said. “The fire was contained to probably about a ten-by-ten square foot area. There was no damage or structural damage to the area at all.”

Operations are on hold while the facility completes its investigation and Occupational Safety and Health Act arrives on scene, Bressner said.