Florida International University pedestrian bridge collapse
On March 15, 2018, a 175-foot-long, recently-constructed section of the FIU-Sweetwater UniversityCity pedestrian bridge collapsed onto the Tamiami Trail, resulting in six deaths, eight injuries, and eight vehicles being crushed underneath.
The initial construction on the pedestrian bridge was located in front of the campus of FIU in University Park, a suburb west of Miami, Florida, United States, and was in the process of post-tension rod adjustment when it suddenly failed. At the time of the collapse, the road beneath the bridge had been open to traffic.
An examination carried out by the Federal Highway Administration discovered faults in the design of the bridge, which overestimated the strength of the bridge in the region that failed and underestimated the load it would be expected to carry. The National Transportation Safety Board issued a "News Release" which said, "load and capacity calculation errors made by FIGG Bridge Engineers, Inc., are the probable cause of the fatal ... bridge collapse in Miami ..." The same day the NTSB released a "synopsis" of its final report, which stated
The New York Times concluded that "the chief probable cause" was "the design by FIGG Bridge Engineers", but that "every company, institution and agency involved in the project was partly to blame for the bridge collapse".
Background
The FIU Sweetwater UniversityCity pedestrian bridge, located just west of the intersection of Tamiami Trail and Southwest 109th Avenue, was planned to connect the FIU campus to student housing neighborhoods in Sweetwater. It was intended to improve pedestrian safety, as the crosswalks at this wide, busy intersection had been identified as a safety hazard, and one student had already been struck and killed by a vehicle. The $14.2 million project was funded with a $19.4 million Transportation Investment Generating Economic Recovery grant from the United States Department of Transportation in 2013, along with state agencies. The bridge cost $9 million to construct, exclusive of the installation cost.The main companies behind the construction project were Munilla Construction Management, a Miami-based construction management firm, and FIGG Bridge Engineers, a Tallahassee-based firm. Unlike most bridges in Florida, the design for this project was overseen by the university, not the Florida Department of Transportation.
Florida International University is known for its expertise in accelerated bridge construction and has attracted international scholars as PhD students. It is home to the federally-funded Accelerated Bridge Construction University Transportation Center, which sponsors industry conferences and seminars. The National Transportation Safety Board, however, found that with respect to the bridge, "F.I.U. had no professional engineers on its staff and relied solely on the expertise of its hired contractors."
Bridge layout
The full pedestrian bridge was to cross both a major roadway and a parallel water canal with two separate spans connected at a faux cable-stayed tower. The main roadway-crossing span was 175 ft long, and the shorter canal span was to be 99 ft long. An elevator and stairs at the south end added 31 ft, and at the north end, 15 feet, for a total bridge length of 320 feet. At the bridge site, the Tamiami Trail roadway has seven lanes of traffic plus one turn lane.The school was on spring break at the time of collapse. The canal span, access ramps, and faux cable-stayed tower had not yet been built. Pedestrian use was to begin when the entire project was complete.The section of the bridge that collapsed weighed and fell onto several vehicles on the roadway below.
Bridge design and construction
The new pedestrian bridge was designed to connect the campus to student housing in a dramatic sculptural way, and also to showcase the school's leadership in the ABC method of rapid bridge construction. The bridge was meant to last more than 100 years, and to withstand a Category 5 hurricane, according to a statement by the university.The full bridge project was styled to look like a cable-stayed bridge, with a pylon tower and high cables for dramatic effect, but functionally and structurally it was actually a truss bridge, with the spans being fully self-supporting. The bridge spans used a novel concrete truss design invented for this project, a "re-invented I-beam concept". Concrete truss bridges are rarely constructed, and few exist. The vertical web of the beam was a series of triangulated concrete diagonal struts along the centerline, and the diagonal angles of the struts varied across the bridge so they would align with pipes from the center pylon, in the eventual faux cable-stayed appearance. The concrete walkway deck was to act as the horizontal bottom flange of a wide I-beam, and the concrete roof canopy was to function as the horizontal top flange of the I-beam. The walkway was thus nearer to ground level than in a standard design where the walkway is placed on top of the structural support system. This reduced the number of steps to climb. The deck was to carry the entire weight of the bridge span, as a tension load. The canopy was to carry the structure's main compressive loads. The diagonal struts would carry either compression or tension forces, depending on their angle and position.
The bridge was a post-tensioned concrete structure. Concrete structures are generally ten times heavier than equivalent steel designs. The bridge was made using a new formulation for concrete intended to stay cleaner than standard concrete formulations. In the main bridge span, the concrete floor deck, roof, and diagonal struts each contained post-tensioning cables whose compressive effect on the concrete could be adjusted after the concrete was cured. Adjustments were expected each time the span was moved onto a different foundation with different support points.
A specification change from FDOT late in the planning phase required relocating both piers of the main span 11 feet north to allow for a future light rail right-of-way near the canal, causing some changes in construction.
Construction of the bridge began in March 2016 and was scheduled to be completed in December 2018. The bridge's main span was assembled adjacent to the highway using accelerated bridge construction. It was lifted into place on the morning of March 10, five days before the collapse, during a weekend closure of the roadway.
Collapse
Reports of cracking
Two days before the collapse, on March 13, the third day after lifting of the main span, the project's lead engineer discovered cracks at the north end of the span. He reported this by voicemail to a Florida Department of Transportation employee. He thought this was not an immediate safety issue, merely something that would need to be repaired later. The FDOT recipient was away for several days and did not hear this message until the day after the collapse.At 9 a.m. on March 15, a university employee heard a loud "whip cracking" sound while under the bridge span, waiting for a red traffic light. At the same time, the design-build team met for about two hours at the construction site to discuss the cracks discovered on March 13. Representatives from both FIU and FDOT were present. The FIGG lead engineer's conclusions were that the structural integrity of the bridge was not compromised and that there were no safety concerns raised by the presence of the crack. FIGG also insisted that no crack repairs should be carried out until the stabilizing of the node and pylon diaphragm with post-tensioning was completed.
The mayor of Miami-Dade County, Carlos A. Giménez, said that workers conducted a stress test on the morning of March 15.
Collapse
At 1:47 p.m. on March 15, the north end of the installed bridge span sagged deeply as the first diagonal fractured, folded, and immediately dropped the heavy full span onto the roadway below. A surveillance video shows the collapse sequence took only a few video frames. As the post-tensioning operation by the VSL company was being carried out on bridge diagonal member support #11, the bottom joint apparently failed explosively, causing the bridge to collapse.United States Senator and FIU adjunct professor Marco Rubio tweeted that engineers were tightening loosened cables on March 15: Workers were adding more tension to the steel rod inside a concrete diagonal strut at the north end. The National Transportation Safety Board, who are investigating the collapse, stated that crews were applying "post-tensioning force" on the bridge before the collapse.
Aftermath
Six people were killed and eight others were injured. Five of the victims were killed immediately when the bridge fell; one died at the hospital. Navaro Brown, aged 37, worked for VSL, the company contracted to apply post-tensioning and died in the collapse. Two other employees of VSL were hospitalized. The other deceased victims of the tragedy were Alberto Arias, 53, Brandon Brownfield, 39, FIU student Alexa Duran, 18, Rolando Fraga, 60, and Oswaldo Gonzalez, 57.At the time of the collapse, the roadway was open, and multiple cars were stopped at a traffic light under the span. Eight cars were crushed. A driver who survived the collapse reported that small rocks fell onto her car just before the front of her car was crushed. A worker saved himself when he heard cracking and locked his safety harness just before the collapse.
Southwest 8th Street between Southwest 107th and 117th Avenues was closed until March 24 while the debris was cleared.
Inquiry
On March 15, 2018, the NTSB launched a Go-team of 15 people to investigate the bridge collapse. The accident number assigned is HWY18MH009. On March 16, 2018 the NTSB Investigators held their first press conference to discuss the inquiry into the bridge collapse. Noteworthy points from the meeting included a statement that the inquiry was in the very early stages, that cracks in the bridge superstructure did not necessarily make the bridge unsafe, that on-site investigations would take about a week, that preserving perishable evidence was crucial, and that bridge workers were applying a "post-tensioning force" on the bridge before the failure. Also on March 16, 2018, the FDOT released a letter to the public with information about the bridge collapse:On March 21, 2018, the NTSB sent out a press release detailing the items from the collapse that required further examination at the Turner Fairbank Highway Research Center, in McLean, Virginia. They also confirmed workers were adjusting rod tension when the collapse occurred.
On May 23, 2018, the NTSB released a preliminary report titled "Highway: Collapse of Pedestrian Bridge Under Construction Miami, Florida " which summarized the accident. They said they are evaluating the emergence of cracks in the region of diagonal members 2 and 11, and the propagation of cracks in the region of diagonal member 11. Pictures of the cracks from February 24 were also given. Consulting engineers Bolton-Perez and Associates, had taken several pictures of severe cracks in diagonal member 11 and adjacent to vertical member 12 which had appeared when the bridge was moved into place on March 10.
The Turner-Fairbank Highway Research Center, at the request of the NTSB, tested samples of steel and concrete from the collapsed bridge, and found that the materials met the project requirements. The NTSB similarly asked the FHWA to examine the design of the bridge. The FHWA examination discovered that the bridge designers had overestimated the strength of one section of the bridge — at the point where the diagonal member 11 and vertical member 12 met the bridge deck — and underestimated the load that that same section would carry.
In June 2019, OSHA released its final report on the FIU bridge collapse and concluded FIGG Bridge Engineers failed to recognize collapse was imminent when they inspected the bridge hours earlier. They also concluded the bridge had structural design deficiencies, severe cracks were wrongly ignored by the Engineer of Record and warranted street closure, and contract bridge design experts violated basic FDOT construction requirements. On October 8, 2019, the NTSB released over 6,000 pages relating to its investigation of the collapse, including letters submitted to the NTSB by the various companies associated with the bridge construction. A final NTSB public hearing on the bridge accident was held October 22, 2019, in Washington, D.C., and concluded "that load and capacity calculation errors made by FIGG Bridge Engineers, Inc., are the probable cause of the fatal, March 15, 2018, Florida International University pedestrian bridge collapse in Miami."
Legal action
On March 19, 2018, the first civil lawsuit was filed against FIGG Bridge Engineers, MCM, Bolton Perez & Associates, the project's consulting engineer, Louis Berger, and Network Engineering Services for reckless negligence.On March 21, 2018, U.S. Transportation Secretary Elaine Chao asked the department's inspector general to probe whether the federally funded pedestrian bridge complied with all rules. A subsequent internal memorandum from the Inspector General of the U.S. Department of Transportation, dated March 22, 2018, expressed concerns the project complied with Federal specifications, and that the objective of an audit will be to assess whether the Florida International University pedestrian bridge met Federal and DOT requirements for the TIGER application, approval, and grant agreement processes
On March 28, 2018, the Miami Herald reported they were denied access to FIU documents related to the bridge construction, citing federal regulations that prevent release of non-public information related to the bridge construction and design project when an NTSB investigation is in progress. A lawyer for Reporters Committee for Freedom of the Press indicated more information should be released under the Florida Sunshine Law, citing intense public interest in the collapse. On May 2, 2018, the Miami Herald filed a lawsuit against FDOT in Florida's Leon County Circuit Court to compel the FDOT to release emails, meeting minutes and other records relating to the bridge's design and construction. On May 3, 2018, a lawyer for the NTSB wrote a letter to Judge Cooper of the 2nd Judicial Circuit of Florida in Tallahassee urging the court to deny a ruling that would favor the Miami Herald plaintiff, for the release of any bridge information generated after a February 19, 2018, cutoff date.
On May 7, 2018, the Miami Herald reported they had received a copy of a memo with photographs from FIU dated February 28, 2018, that had been sent to the Munilla Construction Management company, the bridge project's builder. The memo, which has since been rescinded back from Public view, purportedly urged the bridge engineer to respond to their concerns about significant cracks in the concrete joint at connection between the No. 11 truss and the bridge deck.
On June 4, 2018, Judge Cooper declined to dismiss the Miami Herald case and asked that the NTSB first be given the option of joining the lawsuit either as an amicus or as a defendant.
On June 15, 2018, U.S. Attorney Christopher P. Canova sent a letter to Judge Cooper to request that any rulings in the pending case be delayed until the federal government is able to determine if it should file a statement of interest.
On June 27, 2018, the Travelers Indemnity Company and The Phoenix Insurance Company submitted an 18-page complaint for declaratory relief in U.S. District Court for Florida Southern District, Miami Division. The lawsuit filing seeks to avoid financial liability to the claimants and included the following statement: "There is no coverage under Travelers' and Phoenix's policies issued to Figg for any damages caused by the joint venture and/or partnership between Figg and MCM, as such joint venture and/or partnership was never disclosed to Travelers and Phoenix and does not qualify as an insured under either of the Policies issued to Figg."
On July 26, 2018, the case before Circuit Judge John Cooper was still waiting for Canova's office to file a notice about participating. The case was reassigned to Circuit Judge Kevin Carroll from Judge Cooper.
On July 30, 2018, the NTSB filed a statement of intent supporting the state's motion to dismiss the case. On the following day, Judge Carroll asked all parties to prepare for a ruling later in the week, as he weighed Federal and State law arguments.
On August 21, 2018, Leon County Circuit Judge Kevin Carroll ruled the FDOT "shall produce to The Herald the requested records, but that production shall be limited to records from February 20th to March 15th ". However, two days later and just as the FDOT was about to release documents, the Florida State ruling was temporarily blocked by U.S. District Court Judge William Stafford on a request from the U.S. Attorney's Office for the Northern District of Florida. On October 5, Federal Judge Stafford made a final ruling to block the requested documents.
The following is from a September 18, 2018 OSHA News Release — Region 4: The U.S. Department of Labor's Occupational Safety and Health Administration on Friday, September 14, cited multiple contractors for safety violations after one employee suffered fatal injuries and five other employees sustained serious injuries when a pedestrian bridge at the Florida International University campus in Miami collapsed. The five companies collectively received seven violations, totaling $86,658 in proposed penalties. OSHA cited Figg Bridge Engineers Inc., a civil and structural engineering company; Network Engineering Services Inc., a construction engineering and inspection firm; Structural Technologies LLC, specializing in post-tensioning in bridges and buildings; Munilla Construction Management LLC, a bridge and building construction company; and The Structural Group of South Florida Inc., a contractor specializing in concrete formwork.
A total of 18 civil lawsuits were filed against 25 businesses connected to the failed FIU bridge project. Miami-Dade Circuit Judge Jennifer Bailey is overseeing the on-going case.
On March 1, 2019, Munilla Construction Management, the main Miami-based contractor behind the pedestrian bridge construction, announced a restructuring and recapitalization of the company through a Chapter 11 bankruptcy petition plan of reorganization. The company reached a settlement deal with the victims and their families on May 2, 2019, that would pay up to $42 million.