facebook-pixel

Engineer called 2 days before Florida bridge collapse to report cracking, transportation officials say

(Wilfredo Lee | The Associated Press) Crushed cars are shown under a section of a collapsed pedestrian bridge, Friday, March 16, 2018 near Florida International University in the Miami area. The new pedestrian bridge that was under construction collapsed onto a busy Miami highway Thursday afternoon, crushing vehicles beneath massive slabs of concrete and steel, killing and injuring several people, authorities said.

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.

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, said she had 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 re-occur 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 supposed to take advantage of a faster, cheaper and safer method of bridge-building promoted by the university.

Authorities have not confirmed the victims’ names. The fatalities included a student at FIU. 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.

The bridge was put in place March 10, five days before the collapse.

When finished, the span would have been supported from above, with a tall, off-center 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.

___

Associated Press writers Tim Reynolds, Josh Replogle, Freida Frisaro and Curt Anderson in Miami; Jason Dearen in Gainesville; Tamara Lush in St. Petersburg and Rodrique Ngowi in Boston contributed to this report.

This photo provided by DroneBase shows the collapsed pedestrian bridge at Florida International University in the Miami area on Thursday, March 15, 2018. (DroneBase via AP)

Earlier:

As the 950-ton concrete bridge section was swung into place over a highway last weekend, Florida International University officials were beaming with pride.

The pedestrian bridge on the edge of the Miami-area campus 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 U.S.

“FIU is about building bridges and student safety. This project accomplishes our mission beautifully,” FIU President Mark B. Rosenberg boasted that day. “We are filled with pride and satisfaction at seeing this engineering feat come to life and connect our campus to the surrounding community.”

Five days later, the bridge collapsed onto the busy six-lane highway, crushing cars and killing at least six people in a tragedy now under federal investigation.

While it’s not yet clear what caused the failure of the unfinished span Thursday, the disaster has cast a spotlight on a rapid construction technique widely used around the U.S.

Accelerated bridge construction, or ABC, involves assembling large sections of a span offsite, 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 hardhat workers and motorists 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.”

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.

Professor Amjad Aref, a researcher at the University at Buffalo’s department of civil, structural and environmental engineering, said it is unclear what the builders at FIU were using in lieu of a tower to support the segment that collapsed.

The span had some kind of cables to help support it, and the bridge section that collapsed was attached to two smaller pylons at either end.

But in ABC projects like the FIU span, the loss of the extra support from the main tower during construction is a risk, he said.

“Until all the pieces are put together to transmit the loads safely to the foundations, these bridges may suffer disproportionate or full collapse due to instability,” Aref said. “Typically, this process requires a few weeks. During that time, they are often supported by another system to ensure stability because they are really vulnerable to collapsing.”

“I am really puzzled that the tower does not exist,” Aref said.

Utah started using the ABC technique in 2007 and it has since become the primary way bridges are built, with more than 200 of them around the state, said Carmen Swanwick, chief structural engineer with the state Transportation Department. She said the Miami collapse doesn’t undermine her confidence in Utah’s bridges, which are inspected every two years.

“I have no concerns,” Swanwick said. “We believe it improves quality. A lot of times, the component or the bridge itself is constructed in a more controlled environment.”

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.”

___

Associated Press writer Brady McCombs contributed to this report from Salt Lake City.