Around 5:45am on 11/13 Tower 88 was dispatched to assist Station 15 (Horsham) at an apartment fire with people trapped. CH88 and AC88-1 also responded on the 1st alarm. While en route 15 command struck out the 2nd alarm and Squad 88-1 was added to the response. CH88 took the fire floor while AC88-1 coordinated the pre-planned supplemental water supply in the adjoining housing development. Upon entering the 2nd floor CH88 located the fire in a 2nd floor apartment and closed the hallway door until a 1.75" was stretched.