When the membership of Rivedale Fire Department was asked to participate in the 2010 Joint Service Open House, held at Andrews Air Force Base, they didn't expect to be working hard on a Sunday. The day started and progressed as planned until it was time to leave to go home. As Engine 72 was leaving the base just after 1900hrs, PSC dispatched the box for 9507 Marlboro Pike in company 23's first due. Engine 72 advised their location and requested to respond. PSC granted the request and Engine 72 was the second arriving pulling up right behind the engine from 23. The crew sprinted up and pulled a back up line to engine 23's line. Crews worked quickly to find and knock the bedroom fire in the house, and command scaled back the assignment in 20 minutes to companies 23, 7, 37, and 8. The crew from Engine 72 returned home just after 2100hrs.