Designers Of Collapsed Bridge In Fla. Also Designed Bridges In Minn.

MINNEAPOLIS (WCCO) -- A least six people are dead after a pedestrian bridge collapsed near the campus of Florida International University. Now, we're learning the designers of the bridge also designed the Interstate 35W bridge in Minneapolis.

Search-and-rescue crews in Miami worked through the night, still trying to find survivors. Police say eight cars were trapped underneath.

The bridge was still under construction.

Investigators are looking into whether the accelerated construction method used to get the bridge in place quickly may have played a role.

The bridge was built to make the area safer, after a student was killed last year crossing that street.

CBS News has learned two of the firms that built the bridge have been accused of unsafe practices.

One of the companies, the Figg Bridge Group, also designed and built the Interstate 35W Bridge replacement in Minneapolis after the previous bridge collapsed in 2007, killing 13 people.

Figg also designed the St. Croix Crossing Bridge and the Wabasha Freedom Bridge in St. Paul.

MnDOT deputy commissioner and chief engineer Sue Mulvihill says the bridges were built with redundancy -- or layers -- to ensure safety.

"We have no concerns about Figg," she said. "They would have both hypoxy and steel cables inside the bridge just to hold them together in addition to the fact that the concrete is actually reinforced, and there's teeth in the segments that hold them together."

WCCO obtained the most recent inspection reports for all four bridges and found all were in good condition. The state has made changes since our bridge collapse a decade ago.

"We were diligent before, we're more diligent now," Mulvihill said. "We have increased the number of inspections, we have trained additional inspectors, and so we are very careful about how we design inspect, and do preventive and reactive maintenance on bridges here in Minnesota."

Since the I-35W bridge collapse, MnDOT started peer review, where another contractor reviews original designs before the project moves forward.

In addition, all bridges are inspected at least once every two years. Bridges that are deemed structurally deficient are inspected annually.

The National Transportation Safety Board says it is launching an investigation into the Florida incident and sending specialists to help families affected by the tragedy.