Vanities of the Bonfire - Pushing the Limits: New Adventures in Engineering - page 120

The guys steadying the center pole were also looked to as possible causes of the collapse, but “all
ropes tested were of good quality.” Furthermore, “although one of the guy ropes did fail during the
collapse, it was not a contributing factor because it broke after the collapse sequence had started.”
Texas A&M Bonfire stack, 1994
An incident that occurred a few days before the collapse came under suspicion as well. Witnesses
reported that a crane used to lift logs into place had hit one of the cross ties fastened to the center
pole, breaking off a piece of the tie. However, the commission found that the force that would have
accompanied such an impact “could not have materially affected the center pole or contributed to
the collapse.”
Even a strong wind, an earthquake, ground movement associated with trains passing nearby, and
sabotage were looked to as possible initiators of the accident, but the commission's analysis could
give no credence to such causes. Furthermore, no defects were found in any of the perimeter poles
used to anchor the guys or in any structural member or piece of equipment used in the construction.
In other words, the causes of the collapse were in fact subtle and, according to the commission,
[t]he engineering analysis of the Bonfire collapse turned out to be much more challenging than ori-
ginally anticipated. The physical factors ultimately determined to be drivers of the collapse were
not obvious to the engineering teams at the outset. In fact, it took a number of weeks and consider-
able effort before the collapse mechanism and sequence were determined.