A wildfire that erupted in Northern California forced evacuations as it threatened about 500 homes and other buildings Tuesday, authorities said. The Rices Fire erupted at around 2 p.m. near the Yuba River in Nevada County and had spread to more than 500 acres (202 hectares) by nightfall, said Unit Chief Brian Estes of the California Department of Forestry and Fire Protection. The flames also threatened power lines, water delivery systems and a state park, Estes said.