Instructors Donel Braxton and Cliff Freeman put together a great program for the Officer Level I Fire Investigation class this month. The grand finale was this burn box evolution. They constructed a 10' x 12' room, complete with frame, sheet rock, plywood flooring covered with carpet, and ceiling joists. The room was furnished with a couch, chair, stool, coffee table, and other details like a lamp plugged into an electrical outlet, curtains - and even a Dale Earnhardt calendar! (Incidentally, one of the class attendees couldn't bear the thought of this calendar going up in smoke, so he claimed it prior to the fire being set)

There were several objectives to this evolution. First, it served as great demonstration of basic fire behavior - we viewed all the stages from the incipient to flashover before it was finally extinguished. Second - once the fire was out, Donel and Cliff pointed out the various indicators and clues that fire investigators look at during cause determination.

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THE BURN BOX
The Burn Box	A view from the back	Students get a good look at the burn box
Looks like a typical living room...	...complete with clutter on the coffee table,...	...curtains, and wall hangings (but not the Dale Earnhardt calendar!)	Ceiling joists
The soon-to-be starting point of the fire	A closer view - note the electrical outlet		An interesting experiment. Cliff placed a lit cigarette on this couch at 9:40. Contrary to what one might think, instead of immediately setting the couch ablaze, it just smoldered slightly until finally self-extinguishing at 10:00.
FIRE DEVELOPMENT TIMELINE
13:52:26 - Simulated trash can fire begins	13:52:38 (12 sec. elapsed) - Couch catches on fire	13:54:28 (1 min. 50 sec. elapsed) - Smoke begins to bank down from ceiling. First curtain falls from wall and adds to the couch blaze	13:54:40 (2 min. 2 sec. elapsed) - Fire begins to spread across the couch
13:55:06 (2 min. 40 sec. elapsed) - Rollover visible, chair on right is off-gassing from radiant heat	13:55:18 (2 min. 52 sec. elapsed) - All furniture becomes involved	13:55:28 (3 min. 2 sec. elapsed) - Flooring catches fire	13:55:38 (3 min. 12 sec. elapsed) - Flashover
13:55:46 (3 min. 20 sec. elapsed) - Pretty hot - time to move back...	13:56:00 (3 min. 34 sec. elapsed) - ...and further back still!	13:56:10 (3 min. 44 sec. elapsed) - Extinguishment begins	13:56:18 (3 min. 52 sec. elapsed) - Roomful of fire knocked down in less than 10 seconds with only a few gallons of water
Oops - a flare-up, but quickly re-extinguished		The fire attack crew, members of Fuquay-Varina Fire Department
THE FIRE INVESTIGATION
Clean burn pattern on the wall beside and above the couch indicates complete combustion. Likely the fire burned longest and hottest here.	The trash can was reduced to a melted ring on the floor next to the couch. Also note how the side of the drawers and chair that were facing away from the fire sustained less damage.	Charring on the ceiling joists	Charring on the wall board
The pattern on this wall was caused by the water stream from the attack line	Note how the flooring underneath the stool legs is relatively unscathed	Charring on the furniture - also, that lumpy stuff on the floor is the melted carpet	The right side of the couch sustained much heavier damage than the left due to its closer proximity to the point of origin. Also note the protected area underneath the coffee table.
Another example of a protected area that was underneath the drawers	A closer look at the couch. More burned...	...Less burned	The lamp base distorted and pulled toward the point of origin
Another example of a clue that could point toward the point of origin - more burned on this side...	... and less burned on this side.	A closer look at the carpet and the weird pattern it formed	Cordless telephone handset - VERY well done!
Note that the damage to this wall outlet is only on the front face.	The back, and the wire and connections where a fire would most likely start, are untouched.	A view of the outlet's wall receptacle - undamaged on the inside. This electrical outlet can be ruled out as the cause of this fire.	A single piece of loose scrap carpet had been laying here. The floor underneath remains pristine.
	The outside of the phonebook was completely charred black. But inside, one could still look up phone numbers!