Fire crews work to contain several fires in Placer County

PLACER COUNTY, Calif. (KGO) -- Crews are working to control several fires that have destroyed five homes along Interstate 80 in Placer County.

Officials say five separate blazes broke out Wednesday just east of Auburn and those fires are now threatening a thousand homes.

Some 800 residents in the community of Applegate are under mandatory evacuation orders.

The fires have burned 420 acres and are just 20 percent contained.

It's not clear what caused the fires, but officials are not ruling out arson.