In late January of 2014, the steel arch culvert, sidewalk and retaining wall at 4410 North Tryon Street collapsed. One lane of North Tryon Street was closed due to the collapse. The City of Charlotte contacted Armstrong Glen on February 6, 2014, and asked us for an opinion as to the cause of the collapse. The City had already contacted a contractor to clean up the site, temporarily stabilize the slope, and barricade the area from vehicle and pedestrian traffic. Our engineers visited the the site in order to look for clues as to the cause of failure. Armstrong Glen also provided a brief report summarizing several possible failure scenarios. Armstrong Glen was asked to review shop drawings and calculations from the contractor for compliance with ASHTO, City of Charlotte, and NCDOT design specifications. Reviews were completed, and a reinforced aluminum arch pipe was installed in March 2014.