A 50-acre brush fire broke out in Lake Elsinore on Monday, temporarily closing parts of the busy thoroughfare running through the Riverside County city. 

It was first reported at around 12:40 p.m. near the I-15 and Nichols Road, according to the Riverside County Fire Department. 

The flames quickly spread, ripping through vegetation in the area before firefighters were able to halt the forward progress. As of 9:30 p.m., crews said the fire was 75% contained. 

One firefighter suffered minor injuries while battling the blaze and was taken to a nearby hospital for treatment, according to the department. 

"Firefighters continue working tirelessly to strengthen containment lines and move closer to full containment," said a post on X from Riverside County firefighters. 

The northbound No. 3 lane was temporarily closed due to the firefight, crews said. Multiple water-dropping aircraft assisted in the battle. 

The cause of the fire is under investigation.