The National Institute of Standards and Technology released a draft report today for public comment which identified design flaws in the structure as causing the collapse on May 2 of this year.
Specifically, the wind loads caused by the storm were greater than the capacity of the frame, which eventually led to structural failure of the building.
A total of 12 people were injured, 1 seriously.
The American Society of Civil Engineers (ASCE) recommend a load capacity of 90 mph for this area, yet the report indicates that speeds were in the range of 55-60 mph during the wind event.
"Our investigation found that the facility collapsed under a wind load that a building of this type would be expected to withstand," said John Gross, the head of the study.
The report details a possible sequence of events that led to the collapse:
- Buckling of the inner chord, or inner side of the roof truss, of a frame in a section of the roof on the east side resulted in a kink in the frame.
- Failures of the east and west connections between the side walls and the roof allowed the frame to sway eastward with the wind.
- Compressive failure of the east side at the roof’s ridge led to fractures of the nearby inner and outer chords in the vicinity of the ridge.
- A progression of frame failures throughout the structure resulted in total structural collapse.
Cowboys scout Rich Behm was seriously injured in the accident and is paralyzed below the waist. Special teams coach Joe DeCamillis was also injured, sustaining a neck injury, and is recovering.