A tanker truck transporting some 8,800 gallons of gasoline overturned Wednesday at an intersection near Grossmont College, spilling fuel onto the roadway and forcing residential evacuations, along with a precautionary power shutoff in the area. The accident occurred at Fletcher Parkway and Navajo Road in El Cajon about 9:30 a.m., Heartland Fire and Rescue said in a news release. Emergency crews arrived to find gasoline spilling from the damaged tank of the toppled vehicle and flowing into nearby storm drains, said Andy McKellar, spokesperson for the agency. Paramedics took the driver of the truck to Sharp Memorial Hospital for treatment of injuries of undisclosed severity. Authorities cleared people out of homes within a 300-foot radius of the crash site and advised some residents living farther away to remain inside until further notice, McKellar said. Also, due to potential problems caused by fuel leaking into underground power equipment, utility crews shut down electrical service in the area. County hazardous-materials personnel were called in to deal with the chemical spill, the spokesperson said. The problems caused by the accident were expected to be mitigated by late afternoon, according to McKellar.