Montreal Gazette - Costly mistakes on the Champlain Bridge

Canada's busiest bridge, the Champlain is crossed by 164,000 vehicles daily, as well as 40,000 bus passengers. Within weeks, Ottawa and Quebec will get a report on whether to tear the Champlain down and build a new one. Cost: more than $1 billion.

Saeed Mirza, McGill Dept. of Civil Engineering, who has studied the bridge, said there is little risk the failure of one girder could be catastrophic and cause a chain reaction, bringing down an entire section.

"Such a failure is not probable" because girders are bonded together, so "if one of the girders fails, the load would be transferred to the interior girders which are not as deteriorated as the exterior girders."

Earthquakes are Mirza's big concern. "A major earthquake - 8 or higher on the Richter scale - could pose a high level of risk to the survival of the bridge, which was not originally designed to resist significant seismic loads."