Hammersmith Flyover's collapse risk 'was known to TfL'
3 December 2012 Last updated at 14:15 GMT
A major London road remained open for weeks after a report warned of a small risk it could collapse at any moment.
Hammersmith Flyover, used by 90,000 vehicles a day, was shut on 23 December 2011 as salt water from gritting had rotted internal steel cables.
But a draft report obtained by BBC London showed months earlier Transport for London (TfL) knew it could have seen a "sudden catastrophic collapse".
TfL said monitoring suggested a "number of years of life" left in the bridge.