Billings Fire Department responded Friday to a grass fire behind Bitterroot Elementary School at around 11 p.m. that may have been caused by fireworks.
Battalion Chief Terry Larson said seven other firefighters responded to the blaze.
Larson said multiple neighbors in the area reported hearing fireworks before the fire.
Firefighters were still tending to the fire at around midnight, but Larson said it was contained and that they were waiting for it to burn down a little so they could spray foam.
He urged people to be cautious, as even areas that look green are extremely dry, he said. He also reminded everyone that fireworks are illegal within city limits.