The curve where Amtrak Cascades 501 derailed Dec. 18, killing three people, was identified years ago as an obstacle to Washington state’s dream of creating high-speed rail. The corridor between Lakewood and Nisqually “includes unsuitable sharp curvature,” said the state’s long-range plan, written in 2006. “A new connection, largely on structure because of differences in elevation, with a speed limit of one hundred mph will be required.” Even with $800 million in Obama administration stimulus money, Washington state didn’t rebuild it. The state’s stimulus contracts, released through a public-records request, show the state made no promises to change the curve,...