The number of firefighters battling the Madre fire in the mountains above Azusa tripled Tuesday as crews tried to gain the upper hand on the blaze.
About 450 personnel are now assigned to the fire, which started about 6 p.m. Monday in the steep terrain of San Gabriel Canyon north of Highway 39, according to the U.S. Forest Service.
Unstable winds hampered firefighters' initial efforts, but helicopters dropped crews onto the steep terrain to cut fire lines in an attempt to stop advancing flames.
Los Angeles County Fire Department Inspector Keith Mora said the air assault, which had been stopped overnight when it became too dark to fly, would also resume Tuesday morning.
The blaze has grown to 200 acres and remained just 5% contained.
Wind speeds Tuesday morning were about 10 mph and U.S. Forest Service spokesman Shaun Rollman said those low winds along with double-digit humidity, should allow crews to gain ground on the blaze.