The original design made the bridge difficult to maintain. Morandi encased the cables in concrete, so the corrosion could not be seen or repaired.
But the state of disrepair and crumbling was easily visible well before the collapse.
http://www.global.vidostream.com/Europe/at-least-39-killed-in-italian-bridge-collapse-as-shocking-photos-from-before-tragedy-emerge-10880.html