A firefighter was injured while putting out a massive pallet yard fire in San Bernardino County, authorities said. 

According to the San Bernardino County Fire Department, firefighters were dispatched to the 15000 block of Whittram Avenue in Fontana around 8:15 p.m. Saturday. 

When they got to the scene, crews observed a “stacked pallet yard well-involved with fire,” officials said. 

The blaze was ultimately escalated to a four-alarm fire, eliciting a response from surrounding agencies.

“Upon arriving the arrival of additional resources, it was found that about a quarter-acre of stacked pallets, vehicles, trucks and trailers were burning,” the San Bernardino County Fire Department said in a statement.  “Additionally, three power poles were involved in the fire, which required Edison to handle the hazard as suppression efforts were being initiated.” 

It took about two hours for the 85 responding firefighters to put out the fire, officials added. One firefighter was hospitalized with minor burns, and no injuries to civilians were reported. 

Due to the smoke from the fire, area residents were advised to shelter in place and avoid the area due to road closures and air quality concerns. 

What caused the fire to break out is under investigation.