The FIU bridge collapse on March 15th killed six people, shocking the nation and putting structural engineers on notice. The disaster pressured local governments out-of-state to inspect bridges for safety. Internet commentators and engineering experts worldwide have pored over the limited footage of the collapse to try and make sense of the tragedy. And as can be expected after such disasters, lawsuits have begun in earnest.
The collapsed bridge was the product of a design-build team from two separate companies. Munilla Construction Management and FIGG Bridge Group now both find themselves in the cross-hairs of intense scrutiny.
Florida International University, as well as the Florida Department of transportation, are also under fire. While state law dictates that 180 days must pass before either entity can be sued, a lawyer representing the family of one victim has already declared his intentions to bring them to court.
The collapsed bridge was showing cracks in the structure, days before the incident
The unique design of the bridge compared to others in Florida, coupled with the construction process, are two of the factors that have come under investigation.
The 174-foot span was a truss bridge design variant. This type of bridge is typically made with steel, but the FIU bridge was made with heavy concrete. This was intended to provide improved durability, as well as reduce the difficulty of providing regular maintenance. Additionally, rather than shutting down the road the bridge would span, the structure was built next to its final location. On March 10, less than a week before the collapse, the span was moved into place by transport vehicles.
But within days of installation, problems arose. Less than 48 hours before the actual collapse, FIGG’s lead engineer called the Florida Department of Transportation. In his message, W. Denney Pate reported that cracking was appearing at the bridge’s north end. On the morning of the bridge collapse, FIU and FDOT officials held a two-hour meeting where the cracking was discussed. By the end of the meeting, it was determined the cracking did not pose a significant threat.
Hours later, the bridge would collapse as workers continued progress on the bridge. The 950-ton span crushed cars that were stopped beneath the bridge observing a red light. One worker on the bridge would die, and five commuters would be killed by the heavy concrete.
Instructions and design changes mid-construction may have resulted in the bridge collapse
The bridge was requested to be moved 11 feet north by FDOT to accommodate future planned developments of the road. This necessitated that the lift trucks that would move the bridge to reposition themselves beneath the span. The move request meant that those lift trucks had to move, as they would not be able to drive onto the edge of the road.
What some engineers and commentators believe is that this request may have unintentionally placed even greater stress on the span. Additionally, the design of the bridge contained no safety redundancies. The truss design had no additional structural supports beyond what was absolutely required to keep the bridge standing. And when one of the existing supports did fail, the result was catastrophic.
Lawsuits claim that negligence was a critical factor in bridge collapse
An attorney representing the family of one victim claims that the companies behind the bridge failed to thoroughly consider all aspects of the project. Their lawsuit is joined by others who have echoed similar concerns. The actions of the construction companies involved, FIU, and FDOT are all under suspicion in the eyes of some. Even the construction method of the bridge has been subject to criticism, despite years of successful implementation around the world.
The problem is that the collapse happened quickly, and destroyed the whole span. Any evidence of problems that could lead to the incident could have been destroyed with it. It will take weeks or months before NTSB investigators determine the exact cause.
While the cracking was obviously noted by FIGG’s lead engineer, it is also a common issue with concrete bridges. More often, cracking is a superficial issue. While it may be cause for some alarm, similar bridge designs around the world have operated with such cracks for decades without failing.
If it’s determined the bridge collapse was the result of negligent action, the companies involved could face significant financial losses. But the State of Florida, as well as FIU, are also on the hook. If their own actions over the course of construction contributed to the bridge collapse, they too could see expensive penalties to pay. It’s cold comfort to the families of the victims and the survivors, who still do not understand what happened on March 15th, or why.