The civil infrastructure around us is largely invisible to the general population until those systems fail to perform as they were designed. Such failure results in, at best, inconvenience to end users and, at worst, catastrophic property damage and loss of life. The direct effects of infrastructure failure often lead to legal disputes related to the design, construction, and maintenance of the impacted facilities. On complex disputes, it is the task of forensic experts to understand the causes of the failure and apportion responsibility for the financial losses resulting from the failure. This presentation will highlight a case study in which a facility failed to perform as intended due to deficiencies in design, materials, and construction. The case study will illustrate how a design professional and a cost damages expert collaborated to determine the reasonable cost of repair of a facility and assist with the resolution of the dispute. We will address the design deficiencies that led to the relevant failure and considerations in the design of the repair. The presentation will review best practices for cost estimating in a construction dispute including consideration of escalation, contingency, and substantiation of cost data.