doing a very, very good job. unfortunately, we don t have 100% containment on some of the larg larger fires. natalie asked what makes up these wildfires. we have three major ingredients that make a wildfire spread. may sound obvious, but you have to think about it. the fuel for the fire is needed, the dry grasslands. some of the marshy areas maybe not getting enough rainfall. they can dry out easily. you need the heat for an ignition source. we ve had temperatures soaring in the 80s lately. then oxygen. the air that we breathe is about 21% oxygen. and fire only needs about 16%. so we have plenty of that certainly. here s the latest on the collier county area, where naples is located. 268 personnel actually fighting this fire. 21,000 acres burned, 60% containment. you see that white line right there? that s actually interstate 75. if you ve driven through this area, you know that s a major
and touch a door knob and the spark you get. less energy than that was necessary to ignite that fuel tank. but there is no clear source of ignition on board twa flight 800. by design, only low voltage wires are used inside the fuel tank. however, those low voltage wires pass in very close proximity to much higher voltage wires in wiring bundles. and as the airplane s age and these wiring bundles chafe, you can have occasion where there s arcing or shorting between these wires, which introduce this high voltage into low voltage wire and now you have an ignition source. we don t have a piece of wire or something that we can hold up and say, this absolutely did it. there s not enough left. the ntsb believes and i believe it s most likely a short circuit of the wiring and that certainly was very possible. you look at all the evidence.
take a lot of energy to ignite these vapors. it s less than you feel if you rub your feet across a carpet and touch a door knob and the spark you get. less energy than that was necessary to ignite that fuel tank. but there is no clear source of ignition on board twa flight 800. by design, only low voltage wires are used inside the fuel tank. however, those low voltage wires pass in very close proximity to much higher voltage wires in wiring bundles. and as the airplane s age and these wiring bundles chafe, you can have occasion where there s arcing or shorting between these wires, which introduce this high voltage into low voltage wire and now you have an ignition source. we don t have a piece of wire or something that we can hold up and say, this absolutely did it. there s not enough left. the ntsb believes and i believe
tarmac at the gate with the air conditioners running. and the air conditioners are located right underneath the fuel tank right here so they provide a large source of heat. we did some testing and found out that the temperatures were well over 100 degrees in most of the tank. the temperature rose quickly on the fuel and it is turning to vapor very, very rapidly and filling up the container with vapors, an explosive mixture of vapors. when you provide the conditions together and they introduce a spark in there from any source, it will ignite and burn rapidly. it will explode. in some manner there was a spark. an ignition source. the safety board looked at all types of ignition sources. we looked at bombs and missiles and determined neither was a possible scenario. so our strong suspicion is that
dark smoke billows from the uncontrollable blaze. cannisters shoot up like rockets. most of them were the smaller slnders. they are commonly called a 33-pound cylinder. this site had hundreds of those on site. that s what was rocketing up in the air. my biggest concern is where was the staff? because we couldn t see them coming down. the fire begins during a delivery at a 24-hour propane supply business. there was an accident that released a large amount of propane. so that cloud found an ignition source. that was a vapor cloud explosion. there was a tremendous amount of force. reporter: the initial explosion severely damages several nearby houses. residents are awakened from their sleep and run for their lives. the house actually shook and the windows blew and the door, the glass, it i i fell off my