Complacency and Learning From Mistakes

We usually think only so many mistakes, omissions and oversights can happen simultaneously, not expecting to ever see a case where all failures align themselves, as though links in a chain.

Deliberating on these issues led me to the video of a presentation by Dr. Brian Sheron titled Nuclear Accidents: Lessons Learned on YouTube. Complacency, as Dr. Brian summarizes is one of the leading causes of the catastrophes.

Introduction

Progress of science and technology is making us much more successful in engineering. As occurence of catastrophic failures become rarer, the human nature of complacency kicks in.

In today’s article, I would like to discuss a sad example of the deadly consequences of complacency in engineering. Complacency threatens us in all engineering endeavors, even in professions like Civil Engineering, arguably the oldest profession in the world.

OSHA recently released their report on the Investigation of March 15, 2018 Pedestrian Bridge Collapse at Florida International University, Miami, FL (link to report, PDF). I was totally shocked reading the failures, omissions and oversights by nearly all parties involved in this case while reading the said report by the U.S. Department of Labor, Occupational Safety and Health Administration, Directorate of Construction, Office of Engineering Services.

Bridge immediately before and after the collapse

I would like to seize this opportunity to reflect on what went wrong in this case hoping to draw reminders for construction professionals and lessons from the bitter mistakes leading to the death of 6 and permanent injury of 8 people.

Timeline

Timeline of events leading to the collapse.

Florida International University (FIU) in Miami contracted Munilla Construction Management Inc. (MCM) as the general contractor with the design-build scope for the construction of a pedestrian bridge connecting the campus (one of the largest campuses in the United States) with the City of Sweetwater to facilitate movement of students to the FIU campus.

The general contractor also hired FIGG Bridge Engineers (FIGG), which were the Engineer of Record (EOR). Bolton Perez and Associates (BPA) were also retained by the Client to perform Construction Engineering Inspection (CEI) work.

The design criteria clearly stated that “The design should avoid use of non-redundant, fracture critical members.” However, The bridge was designed with no redundant members. Furthermore, “the selection committee was swayed by the graphics and rendering of the bridge and did not consider the non-redundancy of the structure”.

First cracks were observed between February 24-28 2018, before the truss even left the casting yard. Several Professional Engineers performed an inspection on March 10, 2018 after the placement of the main truss, initially reporting no significant issues. On March 12, 2018, However, an email was sent by the General Contractor to the CEI, citing concern about the cracks.

The cracks seen on the bridge kept growing. These were repeatedly dismissed by the Engineer of Record (EOR). The party responsible for Construction Engineering Inspection work failed to classify the cracks, which were structural in nature. The CEI, was expected to exercise its own independent professional judgement in accordance with their contract with FIU and Florida Department of Transportation (FDOT) requirements.

With intimate knowledge of extensive cracking on the bridge, the CEI failed to recognize that the bridge was in danger of collapsing, and did not recommend to the Client, General Contractor or others to close the street and shore the bridge, regardless of the opinion held by the EOR.

MCM deferred to the decision of EOR and failed to exercise its own independent professional judgement. The contractor had extensive construction experience in concrete structures and had intimate knowledge of the magnitude of cracks, which were growing in size daily.

The General Contractor’s failure to exercise their own independent judgment with regard to implementing necessary safety measures were unreasonable.

Louis Berger (LB) conducted an independent peer review with the “magnitude of consulting peer review fees and time to conduct the peer review were rather constrained, and had an impact on the peer review”. The entire review was conducted by one engineer without any assistance from others LB.

It is interesting to note that neither EOR, FIU nor FDOT raised the issue of why the structural design of the intermediate stage was not checked by Louis Berger. The Client and FDOT may not have known that the intermediate stages of construction were not checked by LB, but EOR knew because LB created the scope of work based on the limited resources allocated by EOR.

Photographs before and after the collapse

As seen from the photographs before and after the collapse, despite the presence of growing cracks and intimate knowledge of the involved parties, no safety precaution is taken regarding road users.

After the collapse, the deck laid 140 feet flat on the floor covering all four eastbound lanes and three westbound lanes. Three of the eastbound lanes were closed to traffic prior to collapse not as a safety precaution but rather to facilitate the ongoing work using cranes.

In conclusion

The series of unfortunate events leading to the collapse of the pedestrian bridge in Miami, Florida seems implausible at first. Records however, reveal how the truth is often more bitter than imagined.

This unfortunate event highlights the need for vigilance in Engineering; how mistakes can have a compounding effect and how detecting them can prove more difficult than thought.

I appreciate everyone that spared time to read through this narrative of the events, as well as those that took time to review the official OSHA report.