WASHINGTON (AP) -- The head of the National Transportation Safety Board is calling the bridge collapse in Minneapolis an "anomaly" and says people shouldn't be worried about general bridge safety.
With that said, NTSB Chairman Mark Rosenker (ROH'-zen-kur) tells the morning talk shows that as a result of this catastrophic disaster, officials will be re-examining safety rules to find out if they should be tightened.
Rosenker says the now-familiar surveillance video showing the collapse is an important clue. He tells NBC it could put the investigation months ahead of where it might be otherwise. He also says it's too early for officials to know if the accident could have been avoided.
More than 75,000 bridges across the country are rated structurally deficient like the span that collapsed in Minneapolis. An engineers group says fixing them could take a generation and cost about 190 billion dollars.