A portion of a storage tunnel that contains rail cars full of radioactive waste collapsed in May, forcing an emergency declaration at the Hanford Nuclear Reservation in southeastern Washington state. Workers later covered the area with dirt before discovering that a second tunnel was at high-risk of collapse.
In this July 9, 2014, file photo, a sign warns of radioactivity near a wind direction flag indicator at the "C" tank farm on the Hanford Nuclear Reservation near Richland, Wash. An emergency has been declared Tuesday, May 9, 2017, at the Hanford Nuclear Reservation after a portion of a tunnel that contained rail cars full of nuclear waste collapsed. Randy Bradbury, a spokesman for the Washington state Department of Ecology, said officials detected no release of radiation and no workers were injured. (AP Photo/Ted S. Warren, file)