Images from Josh Boyajian from the 3-11 Alarm @ 3909 w Harrison this afternoon.
Josh Boyajian photo
Josh Boyajian photo
Josh Boyajian photo
Josh Boyajian photo
Josh Boyajian photo
More images are at this link 2014 Chicago Fires
Chicago 3-11 Alarm fire, 9-25-14
#1 by tom sullivan on September 26, 2014 - 9:06 AM
as said, excellent photos. the bowstring truss has a long history of catastrophic failure under fire conditions. many firefighters have been lost while operating either under, on, or near truss structures. the bowstring truss has design flaws based on faulty assumptions made by engineers concerning the strength of structural timbers used in the construction. they date back to the 1920’s building boom nationwide. as the photos show the front and rear sectors are usually the prime collapse area because of the weakness of those walls. the front and rear are where most of the openings for overhead doors, show windows, etc. are. when failure / collapse occurs many dynamics are in play , that can include a pressure wave that blows out the walls. companies operating in the rear of these building are at risk if in alleys. heavy streams should be worked from gangways or opposite rear yards,, always well out of collapse zones.
tactically, a truss roof (of all types, there are many) must be identified asap. a decision must be made early on how to attack the fire. there have been “saves” of truss roof buildings, but only when the fire has not compromised the truss work. if a heavy stream can hit the fire quickly it might be saved. most times the fire / heat / smoke conditions are such that this is not possible. if fire has gotten above a dropped ceiling it is a lost cause.
there are other factors that influence collapse, deterioration of the timbers, loads on roofs; air conditioning units, snow , built up roofing, etc.
#2 by fred on September 26, 2014 - 8:52 AM
Not absolutely sure, but CNBC is using video of a fire that looks like this 3-11 as part of their story on a fire today at Aurora’s flight control facility.
#3 by B Murphy on September 26, 2014 - 8:00 AM
Great pix. When a bowstring truss roof fails, it fails! Excellent training photos (especially pix 1 and 3) for building construction, fire behavior, tactics, and safety. From the pics, looks like a good operation.
#4 by David on September 26, 2014 - 2:22 AM
Josh, thanks for the photos!