Official noted bridge cracks 2 days before collapse

Florida's Department of Transportation says an engineer left a voicemail two days before a catastrophic bridge failure to say some cracking had been found at one end of the concrete span.

'From a safety perspective… we're not concerned,' engineer said in voicemail

Police set up 3D cameras as investigators begin to digitally reconstruct the scene of the bridge collapse in Miami on Thursday that has killed at least six people. (Joe Skipper/Reuters)

Florida's Department of Transportation says an engineer left a voicemail two days before a catastrophic bridge failure to say some cracking had been found at one end of the concrete span.

However, the agency said the voicemail left on a landline wasn't heard by a department employee until Friday because the employee was out of the office on an assignment.

In a transcript of the voicemail released Friday night, Denney Pate with FIGG Bridge Group says the cracking would need repairs "but from a safety perspective we don't see that there's any issue there so we're not concerned about it from that perspective."

The pedestrian bridge at Florida International University collapsed Thursday, killing at least six people. Authorities are slowly removing the debris, looking for more victims.

Collapsed after 'stress test'

Authorities said the cables suspending the bridge were being tightened after a "stress test" when the 862-tonne concrete span collapsed over traffic in Miami on Thursday.

The $14.2-million US project was supposed to be a hallmark of the faster, cheaper and less risky method of bridge building promoted by the university. Slated to open in 2019, it would have provided safe passage over a canal and six lanes of traffic, and created a showpiece architectural feature connecting one of the FIU campuses and the community of Sweetwater, where many students live.

Multiple vehicles were crushed in the collapse near Florida International University's campus 1:15

As state and federal investigators worked Friday to determine how and why the five-day-old span failed, Florida politicians pointed to the stress test and loosened cables as possible factors, while the local police chief asked everyone not to jump to conclusions.

"This is a tragedy that we don't want to reoccur anywhere in the United States," said Juan Perez, director of the Miami-Dade police. "We just want to find out what caused this collapse to occur and people to die."

'1-of-a-kind engineering design'

Florida Gov. Rick Scott said Thursday that investigators will get to the bottom of "why this happened and what happened." And if anyone did anything wrong, they will be held accountable, he said.

Rubio, an adjunct professor at the school, noted the pedestrian bridge was intended to be an innovative and "one-of-a-kind engineering design."

When finished, the bridge would have been supported from above, with a tall, off-centre tower and cables attached to the walkway. That tower had not yet been installed, and it was unclear what builders were using as temporary supports.

Authorities were removing bodies from the wreckage of the collapsed bridge in Miami, but several cars were still trapped underneath the debris. (Joe Skipper/Reuters)

Andy Herman, a bridge engineer and former president of the American Society of Civil Engineers, told The Associated Press that its so-called "accelerated bridge construction" has been used for years without problems.

He said municipalities like this method because it allows for building a bridge faster "because you're doing a lot of the work in a centralized location where you don't have to worry about being over traffic and then they drive it or lift it into place over the traffic with minimal downtime — so the advantage is that they can build it faster with less disruption to traffic."

The school has long been interested in this kind of bridge design. In 2010, it opened the Accelerated Bridge Construction Center to "provide the transportation industry with the tools needed to effectively and economically utilize the principles of ABC to enhance mobility and safety, and produce safe, environmentally friendly, long-lasting bridges."

Project was a collaboration

The project was a collaboration between MCM Construction, a Miami-based contractor, and FIGG Bridge Design, based in Tallahassee. FIGG is responsible for the iconic Sunshine Skyway Bridge across Tampa Bay.

Both companies have been involved in bridge collapses before.

FIGG was fined in 2012 after a section of a bridge it was building in Virginia crashed onto railroad tracks and injured several workers, according to a story in the Virginian-Pilot.

MCM, meanwhile, was accused of substandard work in a lawsuit filed this month by a worker injured when a makeshift bridge MCM built at Fort Lauderdale International Airport collapsed under his weight. Another dispute resulted in a $143,000 judgment against MCM over an "arguable collapse" at a Miami-Dade bridge project.

The death toll from the collapse rose to six from four on Friday morning. Several other people were sent to hospital. (Joe Skipper/Reuters)

A review of Occupational Safety and Health Administration records shows MCM has been fined for 11 safety violations in the past five years totalling more than $50,000 after complaints involving its Florida work sites.

Both companies expressed condolences for the victims and promised co-operation with investigators.

Bridge put in place last weekend

The university community, along with Sweetwater and county officials, held a "bridge watch party" last Saturday when the span was lifted from its temporary supports, rotated 90 degrees and lowered into what was supposed to be its permanent position.

In a video shared on Twitter Friday, university president Mark Rosenberg said the "tragic accident of the bridge collapse stuns us, saddens us.

"The bridge was about collaboration, about neighbourliness, about doing the right thing," he said. "But today we are sad and all we can do is promise a very thorough investigation in getting to the bottom of this and mourn those who we have lost."