Ten years ago, I visited Texas A&M University the week before Thanksgiving to deliver a lecture in the civil engineering department. After the lecture, my host told me there were two things I had to experience before catching my plane home. One was a famous local barbecue establishment, where the brisket was served with whole cooked onions, a pickle, a wedge of cheddar cheese and a very sharp butcher knife. My host used this utensil to cut, spear and convey the beef to his mouth, all the while joking that he hoped no one would come up behind him and slap him on the back as he was putting it in his mouth. Living on the edge, it seems, was part of the Aggie dining experience.
The second thing my host made sure I saw was the remarkable feat of construction known as the bonfire stack, a log structure, about 50 feet high, that Aggie students build and burn annually as part of the big Thanksgiving weekend football game between A&M and its arch rival, the University of Texas at Austin. My fellow engineer's pride at this wooden marvel betrayed none of the inherent dangers that became so apparent 10 days ago, when it came tumbling down, killing 12 and injuring 27.
The concept of a bonfire was not new to me, for the students at my own university, Duke, were fond of burning fraternity benches to celebrate a victory over their basketball rival from Chapel Hill. On some occasions, these bonfires had gotten a bit out of hand. A particularly dangerous practice involved students, their judgment and coordination impaired by celebratory spirits, jumping through the fire as if in a pagan rite. Some of these students were badly burned one year when they tripped and fell onto the burning debris. In response, the university has varied from banning bonfires to allowing them to proceed under controlled circumstances.
At Texas A&M, the bonfire has been raised to new heights. The tradition was started in 1909 by burning trash. Within a few years, lumber began to be acquired from construction sites. In 1935, an unsuspecting farmer's barn was disassembled for its logs, and the college took control of the bonfire soon thereafter. Since the war years, the bonfire has been constructed as stacks of logs. Early log bonfires were 25 feet tall. But the natural tendency of students and administrators alike is to build upon success, making big things bigger.
Great heights are not readily achievable merely by piling up logs, unless the structures are allowed to be broad at their base, like the pyramids. So that the A&M bonfires could be tall and slender structures--timber skyscrapers as it were--center poles began to be used in the mid-'40s. Rising up much like a ship's mast, the center pole was embedded in the ground and served as a structural core around which the logs could be stacked and lashed. To make taller center poles, and thereby taller bonfires, logs were spliced end to end. In 1954 the logs reached 73 feet high, and a few years after that a bonfire stack collapsed before it could be set ablaze. This warning--that the bonfires were growing dangerously tall--was ignored for another decade, however, with the stacks reaching almost 110 feet tall in 1969. Then the university stepped in and limited the height of future bonfires to 55 feet.
There is a long history of structures collapsing when they grew too large, too steep or too slender. Pyramids, Gothic cathedrals, stone obelisks, timber ships and steel bridges have all met their limits in famous failures. The A&M administration wisely capped the height of bonfires, but even structures well within the limits of scale can fail when complacency, hubris and vanity set in. Building upon anything with a long tradition of success can lead even engineers, who are supposed to know better, into trouble.
The 90-year-old tradition of the bonfire at Texas A&M is one of which the larger community is proud. Many a visitor to College Station has been taken, like me, to marvel at the immensity of the effort and to imagine the heat and light of the bonfire. This year the traditional logs were no doubt being stacked pretty much the same way they had been for some time. The Red Pots, those nine seniors and nine juniors in charge of the construction, would not be likely to innovate too radically, too quickly--for the bonfire stack was a rudimentary artifact with a traditional form. The members of the student crew--some 5,000 workers in all--had to go through safety training. In other words, things can be expected to have been done this year in much the same way as they had been done in years past.
Were the previous failures of the bonfire log stack relevant in 1999? The collapse in 1957 was of a tower of a taller era. A collapse in 1994 was attributed to wet ground. By building smaller and monitoring ground conditions, the lessons of the past were apparently being heeded. So what could have gone wrong?
A commission appointed by the university's president has been charged with conducting "an engineering investigation." No negligence is believed to have been involved in the accident, and the commission is charged with the forensic task of understanding the cause of the failure, "as far as it can be discovered." A report of its findings and recommendations is not expected until well into the spring semester, however, and in the meantime there will no doubt be speculation and supposition, accusation and guilt.
Whatever the precautions, there clearly was plenty of room to err: The center pole could have been flawed or damaged during its erection; the stack, like the Tower of Pisa, could have tilted into an undetected soft spot beneath the ground; some logs could have shifted and disrupted the balance of the stack. Safety guidelines may not have been followed as closely as in the past. Some aspect of the construction process that was not dominant in previous stacks might well have been so in the fatal one.
Even a student-led engineering team is supposed to anticipate such potential faults, however, and take measures to insure that, should they occur, they do not precipitate a collapse. Engineers are also supposed to appreciate the complexity of a structure, even if it may seem as simple as a stack of logs. Exactly what was not properly anticipated or appreciated by the Texas A&M engineers remains to be seen.
Regardless of whether the stack was good or poor engineering, the incontrovertible fact is that it collapsed and killed 12 people. To many an outsider, in retrospect as in prospect, the size of the Aggie bonfire seemed like a great excess. The practice was clearly fraught with danger, like eating Texas barbecue with a knife. But tradition knows little fear and shows little respect for the opposition, whether it be another university's football team or the force of gravity.
Henry Petroski, A.S. Vesic Professor of Civil Engineering at Duke University, is the author of "To Engineer Is Human" (Vintage) and other books on engineers, engineering and technology.