As we commemorate the 25th anniversary of 9/11, we remember the lives lost and honor the heroes who emerged in the aftermath. In the wake of the tragedy, volunteer structural engineers mobilized to help first responders safely search for survivors and remained onsite for months, supporting rescue and recovery operations, collecting critical data, and overseeing the removal of 1.5 million tons of debris. Three engineers who worked at Ground Zero and the Pentagon reflect on the recovery effort, the investigations that followed, and the changes to building codes, standards, and safety practices that continue to shape structural engineering today: go.asce.org/4xOmMi7.