The fire that began Friday afternoon at Roseville's Maidu Regional Park is still burning, officials said Saturday morning.
Four homes and a gazebo were damaged by the wind-driven fire that has charred about 30 acres. The Roseville Fire Department estimated the fire damage between $750,000 and $1 million.
"We made a lot of progress last night. It's 95 percent contained," Assistant Fire Chief Jeff Carman said.
Twenty firefighters are still on site this morning, but they are expected to put out the fire by 8 p.m.
The Fire Department first received a report about 2:25 p.m. Friday of a fire in a nature area behind Maidu Elementary School on Johnson Ranch Drive.
Children were reported to have been seen leaving the area, Carman said, leading to suspicions that the fire may have been set.
A specialized wild land investigator from the California Department of Forestry and Fire Protection has been brought in to investigate.
"We are actively trying to find the origin and cause of the fire," Carman said.
Call The Bee's Richard Chang, (916) 321-1018. Follow him on Twitter @RichardYChang.