New Pedestrian Bridge in Miami Collapses on Thursday, Killing at Least Six

At least six are dead and no more survivors are expected to be found just days after crews had dropped an elevated 950-ton span in place [see photo] on a signature project that was intended to give Florida International University students a safe route across Tamiami Trail (Southwest Eighth Street) to the small suburban city of Sweetwater, where the university estimates 4,000 of its students live, reports the Miami Herald on March 16.

“We know that there are people missing,” said Miami-Dade Police Director Juan Perez, who did not clarify whether the death toll includes those still trapped under the bridge."

The fatalities appear to be motorists trapped in their vehicles, crushed by the 950-ton collapsing steel and concrete span, and at least one construction worker unable to escape.

The 174-foot structure was built alongside the road using accelerated bridge construction techniques while support towers were built at both ends of the crossing. It was dropped into place using cranes on March 10 – "instant bridge," as the Herald described it.

"Until it’s fully secured, a quick-build structure is unstable and requires the utmost precision as construction continues," reported the Herald on Thursday.

Properly shoring up the bridge can take weeks, a period during which even small mistakes can compound and cause a partial or total collapse, said Amjad Aref, a researcher at University at Buffalo's Institute of Bridge Engineering.

"Funding for the $14.2 million bridge, connecting plazas and walkways is part of a $19.4 million Transportation Investment Generating Economic Recovery (TIGER) grant from the U.S. Department of Transportation," noted the FIU press release [pdf] of March 10.

The FIU-Sweetwater UniversityCity Bridge is the largest pedestrian bridge moved via Self-Propelled Modular Transportation in U.S. history

"Speaking at a press conference on Friday, National Transportation Safety Board Chairman Robert Sumwalt said the agency’s team of 15 investigators will be conducting their own probe of the collapse, independent of local authorities," notes the Herald on Friday. It may take months before NTSB can determine the cause of the fatal bridge collapse.

“We are here to determine the cause and make a recommendation to make sure something like this doesn’t happen in the future,” he said.

FIU had selected a design-build team composed of MCM Construction and Figg Bridge Group. The role of the stress test, and whether traffic should have been halted during the process, will be investigated.

An image of the what the finished project would look like is here. The bridge project was the attraction "for building a cluster of apartment towers that cater to FIU students, all to be linked to campus by the new pedestrian bridge," reported the Herald on March 10.