The 500-acre Grant Fire burning in eastern Alameda and Contra Costa counties has destroyed a mobile home, one outbuilding, a trailer and three vehicles as of Thursday morning, according to Cal Fire.
The series of at least seven wind-driven fires started Wednesday afternoon in the Byron area and were 80 percent contained as of this morning, according to Cal Fire.
They were first reported around 1 p.m. in the vicinity of West Grant Line and Mountain House roads in Alameda County and near Camino Diablo in Contra Costa County.
Winds in the area on Wednesday evening were estimated at 30-40 mph, Cal Fire officials said.
The cause of the fires remains under investigation, but no injuries have been reported.