OROVILLE, Calif. (AP) – Officials say they have installed a new emergency siren at a Butte County dam whose damaged spillway forced evacuations earlier this year. The state Department of Water Resources says it will conduct the first test of the new siren at Oroville Dam on Friday. Monthly tests in July and August will follow. The previous siren was lost during water releases in February. Construction crews have begun demolishing the destroyed portion of the main spillway at the dam, which is the nation’s tallest. Huge swathes of the spillway began washing away in February. When a second, emergency spillway also began giving way Feb. 12, authorities ordered the temporary evacuation of 188,000 people downstream. Crews aim to replace the lower spillway by November when high levels of rain and snow return.