Chicago LODD Bow String Truss Examination

[efdcapt115 1,511]

The danger of total collapse involving a bow string truss roof became a graphic reality yesterday in Chicago. The following photos give a glimpse of the peaked bow string roof, and the poor condition of the roof structure. In photo one from the street, you cannot even see that the roof apparently has different structural components and designs. The bow string section is in the rear. In photo two you can see the chimney in the corner of the 3-4 exposure of the fire building in the lower right corner of the photo, partially obstructed by the trees. Disregard where the address is marking the building, the storefront that burned and area of collapse is below it, opposite the parking lot:

Moving closer the shape of the truss becomes apparent. Compare it to the flat roofs immediately surrounding it:

In this photo you can see clearly one of the broken trusses leaning against the far wall inside the collapse zone. Be sure to click through the photo gallery and you will see more evidence of the broken truss system.

http://abclocal.go.com/wls/gallery?section=news/local&id=7858152&photo=1

[R1SmokeEater 359]

Photos from scene:

http://olkee.smugmug.com/Mabas-Division-9-City-Of/Chicago-Fire--3-11/15173631_HxjtG#1134905826_QrHrT

RIP

[grumpyff 1,159]

Here is a link to a diagram and timeline of the fire. Take note of the times and how quick it happened. My linkhttp://www.chicagotribune.com/news/local/ct-met-1223-firefighters-dead-buildin20101222,0,5017573.graphic