The National Transportation Safety Board members that have been investigating a March 15, 2018 bridge collapse at Florida International University have concluded that the design firm FIGG Bridge Engineers, Inc. responsible for the project underestimated the loads created by the bridge's concrete structural system and overestimated the strength of their designs along a critical section that had shown signs of splintering, NBC News reports.

The bridge was, according to previous reports, designed under the Accelerated Bridge Construction (ABC) method that utilizes prefabricated components, a key reason the bridge was built out of concrete and not steel as is more often the case for similar spans.

Prior to the bridge's deadly collapse, investigators found that contractors had discovered large cracks 40-times larger than what is normally accepted for this type of application in a concrete section of the bridge. Despite the cracking, no one involved the project made an attempt to close the road located below the bridge, a critical lapse in protocol that lead to the death of six people. As contractors were working to make modifications to the bridge to control the cracking, the structure collapsed.

NTSB chairperson Robert Sumwalt told NBC News, "The bridge was talking to them, but it wasn't just talking, it was screaming at them. Yet no one was listening."