CNN Anderson Cooper 360 May 25, 2013 00:18:00
They are structurally deficient. bridges like the tappan zee bridge in new york, now being replaced. more than 135,000 cross daily. >> we are absolutely not doing what needs to be done to make sure our bridges are adequately maintained, are safe. >> reporter: stephen flynn wrote "edge of disaster" examining our nation's aging infrastructure, including bridges. >> it's very clear that we have to fix the bridges and keep them adequately maintained because they really are models of engineering in many cases, but when they fail, they really fail. and so it's not just loss of life risk, which is of...