The National Transportation Safety Board’s (NTSB) investigation into the March 15, 2018, pedestrian bridge collapse in Miami, Florida, but the safety agency has already begun confirming some details surrounding the incident.
Among the latest findings is information that workers had been applying a “post-tensioning force” on both ends of the bridge on the day of the tragic collapse that took six lives. Rumors of work taking place at the time of collapse were already swirling, and the confirmation will raise further questions as to why the roadway below was not closed to traffic as workers conducted repairs.
NTSB officials have not commented on any potential collapse causes, but a pre-existing crack in the cement of the bridge has been an area of focus for many experts. As with many bridge collapses, investigators will consider the possibility of a design flaw or a weakness exacerbated during bridge transportation.
Latest NTSB Release Confirms Bridge Work Was Happening While Road Was Open
The NTSB’s most recent information on the Florida bridge collapse came in a March 21, 2018, news release from the agency. The release said that the agency still had investigators at the scene of the accident near Florida International University (FIU) and talked about steps the investigators were taking to secure samples, transport wreckage and find “exemplar” equipment to use in the investigation.
Arguably the biggest news to come from the release, however, was confirmation that bridge workers adjusted tension on not one, but both ends of the bridge on the day of the collapse. The bridge collapsed as the workers were focused on the north end.
The investigative team has confirmed that workers were adjusting tension on the two tensioning rods located in the diagonal member at the north end of the span when the bridge collapsed. They had done this same work earlier at the south end, moved to the north side, and had adjusted one rod. They were working on the second rod when the span failed and collapsed. The roadway was not closed while this work was being performed.
The days since the collapse have seen numerous concerns raised about tension adjustment work being conducted while cars traveled underneath, and critics have been quick to point out how much devastation could have been prevented if the roadway was closed at the time.
According to the NTSB release, recovered components of the bridge and core samples from the materials are being shipped offsite to an investigatory facility in Mclean, Virginia, for further analysis during the investigation (which may take a year or more). Some larger components of the bridge will stay in Florida at a Florida Department of Transportation (FDOT) facility, but the NTSB clarified that only they would have control of those components.
Crack in Bridge Deemed Safe Three Hours Before FIU Pedestrian Bridge Collapse
One particular area of interest in the collapse has been a crack in the north end of the bridge that was discovered two days before the structure fell. Denney Pate, an engineer with FIGG Bridge Engineers who was working on the FIU pedestrian bridge, called a man named Tom with FDOT to discuss the crack on March 13, 2018. Tom was out of the office and Pate left a voicemail that was not heard until March 16, 2018—one day after the collapse.
“Um, so, uh, we’ve taken a look at [the crack] and, uh, obviously some repairs or whatever will have to be done 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 although obviously the cracking is not good and something’s going to have to be, ya know, done to repair that,” Pate said at one point in the voicemail, which was acquired by the Miami Herald. “At any rate, I wanted to chat with you about that because I suspect at some point that’s gonna get to your desk. So, uh, at any rate, call me back when you can.”
Robert Accetta is leading the investigation for the NTSB and was quick to point out that the phone call does not confirm a cause of the collapse.
“A crack in the bridge does not necessarily mean it’s unsafe,” Accetta said.
Engineers with FIGG Bridge Engineers and Munilla Construction Management, who were sharing the project, did discuss the crack with FIU and FDOT, according to the University. FIU says that the meeting happened on March 15, 2018, at 9:00 a.m., just three hours before the collapse, and that the group concluded there were no safety concerns.
Both FIGG and Munilla have expressed their commitment to working with investigators and shock at the collapse, but neither has a flawless safety record. A lawsuit was filed against Munilla in March of 2018 that accused the builder of substandard work that resulted in a makeshift bridge collapsing at the Fort Lauderdale International Airport. FIGG also had a 90-ton section of bridge collapse in 2012 in Virginia, which led to fines.
Lawsuits have already been filed by surviving victims in the wake of the Florida bridge collapse, and wrongful death lawsuits are expected in the coming weeks.
Transportation Secretary Asks for Bridge Audit
Part of the funding for the pedestrian bridge that was to link FIU and the town of Sweetwater was from the Department of Transportation’s Transportation Investments Generating Economic Recovery (TIGER) program. In light of this Transportation Secretary Elaine Chao wrote a letter asking the Office of Inspector General to conduct an audit of the project:
To help inform the Department’s decision making and the public’s understanding, the Office of Inspector General is requested to initiate an audit to examine whether the project owner and the design-build team and contractors responsible for the design, planning, construction, installation, and testing of the FIU pedestrian bridge complied with all specifications and requirements applicable to this project by virtue of the Department’s provision of Federal funding.
In addition to the NTSB investigation, the Miami-Dade police homicide square started a criminal investigation into the Florida bridge collapse, in an effort to determine whether negligence occurred.