Crews fighting the 3,800-acre Williams Fire in the Angeles National Forest are battling in steep and rocky terrain as they try to contain the fire. So far, the fire burning north of Glendora is 24 percent contained.
More than 1,100 firefighters are battling the fire with support from 10 helicopters. Seven firefighters have suffered heat-related injuries.
Because of the rugged, hilly terrain, fire officials say it could take up to a week to contain the fire.
Wednesday, the weather becomes more of a factor. Firefighters have already faced high temperatures and low humidity, but the National Weather Service says there’s a slight chance over the next two days of thunderstorms.
Gusty winds and dry lighting could complicate fighting the Williams Fire and increase the chance that another fire will start.
The cause of the fire is under investigation.
Correction: An earlier version of this story referred to the forest as the Los Angeles National Forest; it's actually named the Angeles National Forest.