The National Transportation Safety Board still has not identified the exact cause of last year's Minneapolis bridge collapse, but this week the agency said it is clear that the bridge's steel gussets, which tie together the support beams,
were not as thick as they should have been. What they don't know, or aren't saying yet, is why the
gussets failed after holding for 40 years.
The big news from the NTSB's findings may be that inspectors nationwide will be asked to go out and look at the gussets of similarly constructed bridges. The feds said
there are about 750 such bridges in the country.
CBS News reported:Transportation Secretary Mary Peters was expected to issue an advisory
urging states to check the gusset plates when modifications are made to
a bridge -- such as changes to the weight of the bridge or adding a
guardrail, said a federal official with knowledge of the plans. The
official spoke on condition of anonymity because Peters had not yet
made the announcement.
Currently, such calculations are done for the entire bridge, but not down to the gusset plates, the official said.
Last August, Peters advised states to consider the additional
stress placed on bridges during construction projects. An 18-person
crew was working on the bridge when it collapsed.
You can use
this MSNBC database to see which bridges in every state have the worst safety ratings.
