Metro Nashville — A 30 foot diameter sinkhole suddenly opened in the center of an industrial park’s loading lot, directly above the junction where 60 inch, 48 inch, and 24 inch sewer trunk lines converge to cross Mill Creek. Thirty five feet below the surface, the existing concrete junction box had deteriorated over time due to significant hydrogen sulfide generation at the confluence of the three lines, ultimately leading to the collapse of the 48 inch main. This emergency project required the contractor to furnish all equipment, materials, and labor to restore the failed 48 inch sewer line. Work included constructing a new cast in place structure, cleaning and lining existing mains, performing associated utility relocations, and maintaining a continuous 17 million gallon per day bypass throughout construction. The presentation will outline the challenges and solutions involved in bidding and executing an emergency repair with limited initial information and rapidly evolving site conditions. It will highlight the investigative strategies, field decisions, and engineering approaches used to piece together the full scope of the failure, restore critical infrastructure, and implement measures to prevent similar issues in the future.