I remeber reading that the fire which was in Coal Bunker 10 (in boiler room 6) was already put out basically at the time of the collision. Aparently though, the fire warped the watertight bulkhead between rooms 6 and 5. Captain Smith was supposed to have told the engineers to rub grease on the area and keep and eye on it.

Author Charles Pellegrino stated that this critical bulkhead was probably made weaker by the fire, and allowed the bulkhead to give away. Aparently, when the ship filled up to boiler room 6, the hull gained almost equilibrium, and the sinking almost came to a standstill.