At 19:31 hours Station 4 was alerted to assist Station 5 (East Whiteland) for reports of smoke in an office building in the unit block of Great Valley Parkway in East Whiteland Township. Also due on the assignment were Station 3 (Paoli) and Station 2 (Berwyn) for an Engine.

The county advised responding units of a caller reporting smoke in a hallway. Crews from 5,4,3 & 2 arrived and investigated the source of the smoke. Crews from 5 and 3 investigating the interior of the building while the crew of Ladder 4 was sent to the roof. Engine 2-1 established the Rapid Intervention Team.

After a brief investigation the source of the smoke was determined to be an issue with one of the HVAC units. That unit was secured and the assignment was placed under control. Malvern units cleared the scene a short time later.