Flames from a vegetation fire forced the evacuation of a Spring Valley preschool on Thursday afternoon.
After the fire was out, investigators announced they suspected the blaze was sparked by an arsonist in a canyon just off Sweetwater Springs Road and Rothgard Road.
The fire, which was started before 1 p.m., threatened several homes and businesses in the area, including a KinderCare day care. Nearly 40 children and teachers were forced to evacuate the structure, which is on the edge of the canyon. Firefighters extinguished the fire as it was racing toward the school's playground.
The fire was easy to control, thanks to neighbors who had just cleared brush from around their homes, creating a defensible space, firefighters said.
A half-acre was charred by flames. Investigators are still looking into the cause of the fire.