Firefighters gain the upper hand on 400-acre Sierra fire near buildings in Fontana

A 400-acre brush fire temporarily threatened some buildings in Fontana, near the Jurupa Hills Regional Park area, on Sunday.

The fire, called the Sierra Fire, was first reported around 3:30 p.m. near Sierra Avenue, south of I-10, according to San Bernardino County Fire Department officials.

The field size quickly increased from one acre to 40 acres by 4 p.m. and climbed again to 350 acres by 6:30 p.m., triggering a second alarm response from firefighters, including support from the State Fire Department. Riverside County.

According to the San Bernardino Fire Department, the fire is at least 80 percent contained.

The fire is spreading southeast “with moderate expansion of the side slope to the east,” firefighters said.

Crews were previously deployed to homes in the area in case the fire moved toward them, but they say the threat to structures has been mitigated.

Following the shooting, Fontana police closed Sierra Avenue at Jurupa Avenue to the public. It should be reopened at 10 a.m. Monday.

Crews say structures are threatened by spreading flames, but no evacuation orders have yet been issued.

Due to the size of the fire, the South Coast Air Quality Management District has issued a wildfire smoke advisory until Monday afternoon.

The advisory was issued for parts of San Bernardino and Riverside counties, including the communities of Fontana, Jurupa Valley, Bloomington, Rialto and Colton.

People living in these areas are advised to stay indoors with windows and doors closed. Authorities advise people to avoid vigorous physical activity and to run air conditioning while smoke persists.