Sierra Fire: 400-acre blaze erupts in Fontana, containment reaches 80% after homes threatened

FONTANA, Calif. (KABC) -- A 400-acre brush fire burned Sunday in Fontana, burning dangerously close to homes before being 80% contained, officials said.

The so-called Sierra Fire erupted near the intersection of Sierra and Jurupa avenues, less than two miles south of the 10 Freeway. No injuries were reported.

"Structure defense engines in place," the San Bernardino County Fire Department said on X at 3:42 p.m., adding that the fire was burning in a southeast direction with "moderate side slope expansion to (the) east."

Video from AIR7 showed flames burning on a hillside near a row of houses, with only a retaining wall standing between the homes and the fire.

Fixed-wing aircraft were seen dropping pink Phos-Chek at the scene as firefighters on the ground marched toward the fire line on foot.

No evacuations orders were issued.

The fire was 15% contained as of 6 p.m. and structures remained threatened, according to the Fire Department. Additional ground resources and aircraft were requested.

Just over three hours later, the containment level had risen to 80% and the structure threat was mitigated, officials said.

"Firefighters remain on scene thru the night to mop-up and reinforce containment lines," the Fire Department said on social media. Sierra Avenue was scheduled to reopen at 10 p.m.

The cause of the fire was not immediately known.