Arson suspected in CoCo grass fire

Arson investigators are looking into the cause of an early-morning grass fire in Contra Costa County, the latest in a string of blazes that may have been deliberately set. The fire, near Marsh Creek Road between Morgan Territory and Deer Valley roads east of Mount Diablo State Park, began around 12:30 a.m. and scorched 4 acres before being brought under control about 90 minutes later. No structures were damaged.