At 0251 hours, Truck 1 was requested for the RIT assignment for the apartment fire. Upon arrival command requested the Truck crew to check for extension on the 3rd floor. As crews got to the 3rd floor they recognized a strong need for ventilation as well as a need to open up the pipe chases. After opening up the Truck crew made its way to the 2nd floor to find the same conditions and began opening up. Truck 1 cleared at 0400 hours.