The fire spanned 400 acres and was at 80% containment just after 9 p.m. according to Eric Sherwin, public information officer for the San Bernardino County Fire Department.
Meanwhile farther north, in Fresno County, the Basin fire was one of the two largest fires in the state, which continued to grow just as brutal temperatures were expected in inland parts of California this week.
The Fontana fire, dubbed the Sierra fire, was first reported around 2:30 p.m. near Sierra and Jurupa avenues south of the 10 Freeway. The fire was driving up the slope of a hill and buoyed by a breeze once it reached the top, Sherwin said.
Although there was no damage reported Sunday, officials had warned that structures could be threatened but stopped short of calling for evacuations. By late Sunday, the structure threat was “mitigated” and firefighters remained on the scene to reinforce containment lines, according to Sherwin.
Two firefighters were transported to a local hospital for minor injuries, he said.
The cause of the fire is still unknown. Sherwin urged caution amid record-high temperatures in parts of the state where dried-out grass could easily ignite and spread. A spark from a lawnmower could be enough to start a brush fire, he said.
“Southern California is ready to burn. These fires are everywhere,” he said. “Everything we can do to prevent a fire from starting is one less fire that has the potential to threaten homeowners.”
On Saturday, a fire broke out in Moreno Valley in Riverside County and scorched more than 200 acres. It was among about 10 fires burning across the state over the weekend, according to Cal Fire.
The largest of the blazes were in Fresno County, where the Basin fire that ignited on Wednesday had destroyed nearly 12,000 acres by Sunday night and had not been contained, according to CalFire.
Also in the Central Valley, the Fresno June Lightning Complex fire, which started Monday, had scorched more than 10,600 acres, according to CalFire’s latest update. Officials had contained 61% of that fire as of Sunday night.