Authorities are searching for what went wrong in Thursday’s deadly bridge collapse in Miami.
Experts are focusing on two questions: why the pedestrian suspension bridge at Florida International University was not supported by a central tower and why vehicles were allowed to drive on the street below even while the construction was being tested.
As seen in the footage above, a 175-foot long section of the FIU–Sweetwater UniversityCity Bridge collapsed onto US Route 41, crushing several cars and killing six people.
Miami Commissioner Xavier Suarez, a civil engineer by trade, was incredulous that the road was not closed while work was being done on the bridge.
Collapse of a brand-new pedestrian bridge w/o pedestrians on it @ FIU makes no sense. I will not accept explanation based on “testing.” U cannot “test” bridge when people are driving below it. I want 2 know what failed – support or span? Either way, somebody was beyond negligent.
— Xavier L. Suarez (@XavierLSuarez1) March 16, 2018
Dr. Amjad Aref, a civil engineer at the University of Buffalo’s Institute of Bridge Engineering, told the New York Times that the public is generally kept out of the work area when a bridge is being stress tested, as the FIU bridge was.
“Normally when we do anything, even a fairly completed bridge or if it’s some rehab or even really minor load-testing, there’s some sort of traffic control,” he said.
One factor being examined as a possible cause of the collapse was the lack of a central tower, which, along with cables, is usually put in place early during the construction of a suspension bridge in order to keep it in place.
Last week, the university posted a rendering of the completed bridge to Twitter, showing that it was intended to include a tall central column with cables.
This Saturday, we'll be positioning a 174-foot section of the FIU-Sweetwater UniversityCity Bridge. We're about to get a new #FIUview and an extra 9,900 square feet of gathering/event space! pic.twitter.com/E3DQ6GYFUj
— FIU (@FIU) March 8, 2018
Andrew Herman, a former president of the American Society of Civil Engineers, told USA Today that it seemed the builders did not follow the proper sequence in putting the bridge up.
“When you’re doing staged construction like this, what you have to make sure is that at each stage that the structure is strong enough for the loads that are on the bridge.
“The engineering, both design and the construction engineering, should have taken that into account with the bridge in that condition.”
Aref suggested investigators would quickly find the cause of the collapse.
“From a structural-engineering point of view, the forensic engineers won’t take long to figure out what happened,” he said.
According to ABC News, the lead engineer working on the bridge called the Florida Department of Transportation (FDOT) about cracking he noticed in the structure.
W. Denney Pate of FIGG Bridge Group left a voicemail on Wednesday, but the FDOT staff member was out of the office on assignment and did not hear the message until Friday–a day after the collapse.
In a statement, FDOT said:
“The responsibility to identify and address life-safety issues and properly communicate them is the sole responsibility of the FIU design build team.
“At no point during any of the communications above did FIGG or any member of the FIU design build team ever communicate a life-safety issue.”
In an interview with WIOD, director of the Miami-Dade Police Department, raised the possibility of bringing criminal charges against those responsible for the tragedy.
His first priority was clearing the area and getting the dead to their families.
“We just want to get those bodies out of there so [families] can have their loved ones one last time,” he said.