Further to Whistle Stop's post--and hats off to you for your SAR work--I would add the following.

It has been SOP to vent structures in many circumstances to release heat/gases which action concomitantly allows air (O2) in. Venting means that a 4' x 4' hole is cut in the roof of a burning house (it's 8' x 8' for bigger structures like industrial buildings). The two dozen houses, all alike in construction have provided an opportunity for the the NYFD to help Underwriters Laboratories and some other agencies that test firefighting equipment and procedures to see if the SOP is a good one. Once holes are put in burning structures, the behaviousr of fire in those structures changes. The NYFD has loaded each house with the same materials (furniture) in the same places and one by one they will be lit afire and the fire's progress recorded on film using IR photography, etc., to determine which procedure would be safer to follow. Basically, to vent or not to vent. Traditional wisdom has it that venting should occur asap. This has been questioned over the past few years and hopefully the results will settle the questions one way or the other. The firefighters operating at the tests site (Governor's Island) will benefit from it as a training exercise and the testing organizations will gather data as the various fires proceed and different methods of fire suppression applied.

Flash over happens when a room reaches a temperature of about 1100 degrees. Particulates and gases in the air burst into flame in the same second to second and a half as do all other combustables in the room. The chances of surviving a flash over are between slim and none. Since the primary intent at structure fires is to

1) save civilian lives
2) save property
3) save adjacent property

all the while keeping the firefighters safe, the results of the study will be important not only to the NYFD, but also all firefighting organizations around the world.

PS The fire tetrahedron gives us four conditions necessary for sustaining fire: heat, fuel, oxygen and sustained chemical reaction. Remove any one of those things and the fire goes out. So the tests will keep detailed records of the variables and thus present a scientific approach to see if what fire departments have done for years is actually the best and safest way to handle situations.