A tanker truck overturned at Dublin in Alameda County, spilling an estimated 1,000 gallons of toxic, flammable vinyl acetate and forcing closure of Interstate 580 that carries thousands of commuters to San Francisco. About 500 people were evacuated, authorities said. At least 10 were treated at Valley Memorial Hospital in nearby Livermore after complaining of burning eyes and nausea. The California Highway Patrol began reopening lanes on I-580 about six hours after the 1 a.m. spill. Evacuees were allowed to return home after 9 a.m.