A strong earthquake shook Hawaii early Sunday, causing a landslide that blocked a major highway on Hawaii Island and knocking out power across the state, authorities said. The state Civil Defense had unconfirmed reports of injuries, but communication problems prevented more definite reports. People were also trapped in elevators in Oahu, authorities said. Gov. Linda Lingle said in a radio interview with KSSK from Hawaii Island that she had no report of any fatalities. She said boulders fell on highways, rock walls collapsed and television had been knocked off stands. Lingle has issued a disaster declaration for the entire state of Hawaii.