Engineer tried to warn of cracks in Florida bridge

MIAMI - An engineer left a voicemail two days before a catastrophic bridge failure in Miami to say some cracking had been found at one end of the concrete span, but the voicemail wasn't picked up until after the collapse, Florida Department of Transportation officials said Friday.

The voicemail left on a landline wasn't heard by a state DOT employee until Friday because the employee was out of the office on an assignment, the agency said in an email.

In a transcript 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."

At a news conference Friday night, officials from the National Transportation Safety Board said they have just begun their investigation and cannot yet say whether any cracking contributed to the collapse. They also said workers were trying to strengthen a diagonal member on the pedestrian bridge at Florida International University when it collapsed.

Robert Accetta, the investigator-in-charge for the NTSB, said crews were applying post-tensioning force, but investigators aren't sure if that's what caused the bridge to fall.

In a news release late Friday, FIGG Bridge Engineers said it "continues to work diligently" to determine the cause of the collapse and is examining the steps its team has taken. It added, "The evaluation was based on the best available information at that time and indicated that there were no safety issues." It also asked for time to accurately determine what led to the accident.

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

A college student who narrowly escaped from a car that got smashed in the collapse said he watched helplessly as the structure tumbled down on top of the vehicle and killed the friend who was sitting next to him in the driver's seat.

Richie Humble, who studies at FIU, was riding in a car under the pedestrian bridge when he heard a long creaking noise coming from the structure that spanned a busy Miami-area highway. It sounded different from anything he had ever heard before.

"I looked up, and in an instant, the bridge was collapsing on us completely. It was too quick to do anything about it," Humble said Friday in a phone interview with The Associated Press.

The family of the driver, Alexa Duran, has said she died. Once Humble realized he was alive, he also realized that he could not get to Duran. He called to her but got no response. A group of men outside the car started yelling at him to try crawling through the rear window.

He made his way into the back seat but couldn't squeeze through because the window was crushed. The men outside grabbed a wooden plank and pried open the rear door to pull him free, he said.

"I was trying to get people to realize my friend was still in there," he said.

He suffered cuts to his leg from glass and a slight fracture to a vertebra, but he was able to walk away from the scene.

While families waited for word on their loved ones, investigators sought to understand why the 950-ton bridge gave way during construction. The cables supporting the span were being tightened following a "stress test" when it collapsed, authorities said.

The DOT said in its Friday release that it had not been notified of any stress test.

"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."

Detectives declared the rubble a homicide scene.

Scheduled to open in 2019, the bridge would have provided safe passage over a canal and six lanes of traffic and created a showpiece architectural feature connecting the campus of FIU with the community of Sweetwater, where many students live.

The $14.2 million project was a signature achievement of the school's Accelerated Bridge Construction University Transportation Center, a research group set up with federal funding a few years ago to show how spans could be built faster and cheaper in the United States.

"FIU is about building bridges and student safety. This project accomplishes our mission beautifully," FIU President Mark B. Rosenberg boasted March 10, the day the bridge was swung into place. "We are filled with pride and satisfaction at seeing this engineering feat come to life and connect our campus to the surrounding community."

While it's not yet clear what caused the failure of the unfinished span five days later, the disaster has cast a spotlight on a rapid construction technique widely used around the United States.

Accelerated bridge construction, or ABC, involves assembling large sections of a span off-site, then moving the massive pieces into place all at once.

The technique eliminates the lengthy road closings and other traffic disruptions that can result when a bridge is built out over a highway piece by piece. It is also considered by some engineers to be safer for hard-hat workers and drivers because much of the construction isn't done in the middle of traffic.

The general approach has been around since the mid-19th century - and has been used safely and successfully for a long time - but interest in ABC has increased in recent years as states have looked for quicker, less expensive ways to replace thousands of aging bridges.

In the case of the Florida tragedy, engineering experts said the question is where was the fatal mistake: in the design of the bridge, in the way its construction was carried out or in the materials used?

Civil engineering experts who viewed photos of the planned structure and the collapse have raised questions about how FIU and its contractors approached the project.

To some bridge engineers, the decision to install the span's main concrete segment over a busy road before building its main support tower was puzzling. Traditionally, the tower is constructed first and the walkway or roadway is anchored to it with cables.

"It's odd," said Henry Petroski, a professor of civil engineering at Duke University and a leading authority on engineering failures. "That's probably why they used this so-called ABC method, so they could get the span over the roadway in one operation, because if you do it incrementally, you have to interrupt traffic."

It was unclear what builders were using as temporary supports.

Investigators will also be looking at the companies building the project, a collaboration between MCM Construction, a Miami-based contractor, and Figg Bridge Design, based in Tallahassee. Both companies have been involved in construction accidents before.

Figg was fined in 2012 after a section of a bridge it was building in Virginia fell and injured several workers. Virginia's labor department later fined Figg for construction violations, and a subcontractor sued accusing the firm of negligence and poor design. MCM was accused of substandard work in a lawsuit filed this month by a worker injured when a makeshift bridge the company built at the Fort Lauderdale airport collapsed under his weight.

Engineers say the method has been used safely in other projects for years, and in general keeps the public safer.

"What really bothers me is with ABC, the benefits are so substantial that I would hate to see this accident lead to its reduced use," said Michael Culmo, a bridge engineer in Connecticut who has worked on accelerated construction projects for decades. "While this is a tragedy, the process itself is very safe."

Authorities have not confirmed the names of victims. One person died at a hospital, and Perez said five bodies were located with the help of cameras but had not yet been retrieved.

In a Facebook post, Chelsea Brownfield said she was awaiting any information about her husband, Brandon. According to a Go Fund Me page set up for the family, Brandon Brownfield was driving home from work when the collapse happened.

"The outpouring of love we have received is incredible," Chelsea Brownfield wrote. "I know you are all concerned for us. We still have not received any news or updates about Brandon Brownfield or the progress of the search (and) rescue."

The post ended with the hashtag "praying for a miracle."

Brownfield declined to comment in a message to The Associated Press.

Jorge and Carol Fraga feared their relative's car was trapped beneath the bridge. Jorge's 60-year-old uncle, Rolando Fraga, lives in the area and frequently takes the nearby turnpike to work, but no one has heard from him since midday Thursday.

"The waiting is so ... I don't have words for that," Carol Fraga said through tears.

Bridge: Families wait for news of loved ones who didn't come home