At 18:02, Engine Company 41, 45, and Truck 45 responded to W Willow St for an automatic fire alarm. Headquarters advised that the call was received by a neighboring residence that reported the alarm was triggered. Company 41 arrived on scene and found normal conditions. Shortly after crews launched their investigation, they requested Carlisle Police Department to the scene. Crews made their way into the rear of the structure and the normal conditions were consistent on the interior. Crews continued their investigation until 18:21 before returning available.