A large blaze erupted at a power substation in Pittsburgh after a reactor "catastrophically failed," public safety officials announced.

The fire erupted around 8 p.m. Monday and continued to burn overnight at the Duquesne Light Company substation on Brunot Island, a small island in the Ohio River, which runs through Pittsburgh, a company spokesperson said.

Footage from CNN affiliate WTAE shows a large plume of thick, black smoke wafting from Brunot Island toward the city's downtown area.

The fire was caused by an "issue with a specialized transformer," Duquesne Light spokesperson Ashley Macik said in a statement to CNN.

No injuries or power outages have been reported, Macik said.

"Safety continues to be our top priority -- for our customers, employees, the public and also the environment," Macik added. "We are continuing to investigate the cause and monitor any further impact."

The fire and any hazards are contained to the island, Pittsburgh Public Safety said in a tweet.