File--In this Aug. 1, 2012, file photo, several bridges spanning the Willamette River are shown in Portland, Ore. There are numerous bridges in Portland crossing the river, varying in age and ability to withstand a major earthquake. When North America’s undersea edge and a tectonic plate pushing beneath it inevitably give way to three centuries of accumulated stress, unleashing a monster earthquake and tsunami in the Pacific Northwest, the expected catastrophic loss of life and economic disruptions could be lessened by an early warning system. (AP Photo/Don Ryan, file)