The communications center alerted Station 13, Engine Delco 66, Engine 25, Engine 39, Rescue Delco 40, Tower 11 and Rescue 20 for the RIT assignment for a working residential fire. Rescue 20 made the response under command of Deputy Chief Willis with a crew of 5. While responding, Claymont Command requested a 2nd alarm assignment and had extension into the D-1 exposure. Rescue 20 arrived and assumed the RIT responsibilities. A Mayday was declared due to a structure collapse of the main fire building, which had companies operating in that area. Command quickly lifted the mayday after a PAR check was completed and all units were accounted for and unijured. Rescue 20's crew stood fast and no deployment was neccessary. Rescue 20 was placed back to service after a few hours. 13-8 (Haley "Ceaser") had the Claymont Command