Why the Dallas Cowboys training facility collapsed

Readers who follow football may recall that the training facility for the Dallas Cowboys collapsed last spring during a practice, causing injuries and a lot of conjecture about the causes. The collapse took place during a wind storm but the winds were well below the design extremes.

The National Institute of Standards and Technology sent a team in to study the structural failure. They recently released a report on their findings. Among the high points:

"Assumptions and approaches used in the design of the Cowboys facility led to the differences between the values originally calculated for the wind load demand and structural frame capacity compared to those derived by the NIST researchers. For instance, the NIST researchers included internal wind pressure due to the presence of vents and multiple doors in their wind load calculations because they classified the building as "partially enclosed" rather than "fully enclosed" as stated in the design documents. The NIST researchers also determined that the building's fabric could not be relied upon to provide lateral bracing (additional perpendicular support) to the frames in contrast to what was stated in the design documents and that the expected wind resistance of the structure did not account for bending effects in some members of the frame."

You can find a press release about the findings here, along with a link to the full report:

http://www.newswise.com/articles/view/557082/?sc=swtr;xy=5017520