Great video to illustrate exactly how ventilation effects fire spread. Pay attention from about the 3 minute 27second mark.
On YouTube this is titled “Fire Fighter Freelanced Ventilation”. I don’t know if this was freelancing, was an ordered act, or a case of lack of knowledge of fire behavior married with a SOG that encourages implicit coordination. What is clear is that we can see EXACTLY how ventilation works. When you open up, the smoke and trapped heat flow out the opening. If that is not channeling the superheated products of combustion out of the building in a controlled manner then we are going to spread the fire.
Take the time to study these videos when you find them. We only get to see a very small number of fires during the course of our operations. These videos are a good way for us to watch, replay, study and learn.