Investigators with the National Transportation Safety Board said they are still in the early stages of their investigation and have not yet determined the point of failure on the pedestrian bridge that collapsed Thursday over the Tamiami Trail, killing at least six people.
Speaking at the campus of Florida International University on Friday night, the investigators also said they have not been able to independently confirm that there was cracking in the structure, a revelation that was uncovered Friday night when the Florida Department of Transportation released a voicemail from an engineer with the firm that designed the structure. The engineer left the message two days before the bridge collapsed.
“A crack in the bridge does not necessarily mean it’s unsafe,” Robert Accetta, an NTSB investigator, said.
NTSB Chairman Robert Sumwalt said the on-site part of the investigation would likely take about a week. He said the agency’s focus is on figuring out what went wrong and how to prevent a similar catastrophe from happening again.
“Once our team leaves here, that’s really just the beginning of the investigation because there’s a lot of work that goes into this,” Sumwalt said. “This will be a very complicated and very extensive investigation.”
While they’re still in the early stages, some details have emerged. Crews were working on strengthening the suspension cables on the northern portion of the bridge when it collapsed.
“Our mission is to find out not only what happened — we know what happened. The bridge collapsed. We want to find out why it happened,” Sumwalt said. “Our entire purpose for being here is to learn from these things so that we can keep them from happening again.”
One way of doing that, Sumwalt said, is for his team to document what he called “perishable evidence,” which he defined as “evidence that goes away with the passage of time,” while they are in South Florida.
“This bridge will not be here in a few days,” Sumwalt said. “It will be out of the way, so we need to document those things that we can while that evidence is there.”