A firefighter suffered minor injuries in the 247-acre Marsh Fire, which started Wednesday afternoon in unincorporated Contra Costa County south of Clayton and is 60 percent contained as of Thursday morning, according to Cal Fire.
Fire crews stopped the forward progress of the blaze on Wednesday night after it started at 2:41 p.m. in the area of Marsh Creek and Morgan Territory roads.
One residence and three outbuildings have been destroyed and about 100 other structures remain threatened as of 7 a.m. Thursday, Cal Fire officials said.
Although containment numbers are up from 20 percent on Wednesday night, mandatory evacuation orders are still in place for Marsh Creek Road between Morgan Territory Road and Gill Drive.
Evacuation centers have been set up at the Clayton Library at 6125 Clayton Road and at the Brentwood Community Center at 35 Oak St.
About 180 fire personnel in all have responded to the blaze, according to Cal Fire.