SANTA ROSA, California (AP) – Airplanes dropping water and fire retardant have joined the battle against a destructive wildfire burning on the western side of Los Angeles.

Night-flying helicopters made water drops during predawn hours Monday and large aircraft started flying the area after the sun rose.

Two so-called “Super Scooper” turboprop airplanes that scoop up water from lakes and reservoirs have begun making drops, along with converted jets unleashing loads of bright pink retardant.

The fire erupted around 1:30 a.m. in Sepulveda Pass where a highway passes through the Santa Monica Mountains and roared up slopes into canyon and ridgeline neighborhoods including Mountaingate and Brentwood.

About 10,000 homes and businesses are in areas subject to mandatory evacuation orders.