Mall collapse delivers infrastructure warning
Engineers’ judgments about the safety of existing structures are basically prognostications fraught with uncertainty. Indeed, they usually are carefully phrased to ensure their clients understand the degree of uncertainty involved.
The cost and societal implications of condemning a structure like, say, Toronto’s Gardiner Expressway are immense, as indeed would have been condemning the Algo Mall in Elliot Lake, which collapsed last year and killed two people. Sometimes decisions are akin to the hope of a Band-Aid on a slow cancer, the optimism is based solely on the slowness and uncertainty of the cancer’s growth.
The collapsed portion of the Elliot Lake mall was a traffic deck that also served as the building’s roof. All exposed structures, from the time they are put into service, are subject to deterioration, and existing ones were constructed at a time when designers, architects and engineers had limited experience with the long-term effect of corrosion.
Worse, designs and materials (unprotected steel and ordinary concrete) have turned out to be inadequate for long life. Most have now passed their “risk free” life and are ticking time bombs, acceptable only because the alternative — to rebuild to new standards — is not seen as economically feasible. Instead, owners, public or private, continue with expedient remedies. But make no mistake, there is considerable public risk, as the Elliot Lake mall demonstrated.
The response to deterioration usually involves patching and the acceptance of some leakage, as opposed to paying the costs of a major restoration. Budgets determine what is done. The evaluation and maintenance of such structures are not high-priority items and history shows that maintenance often is dropped or cut back. In these cases, it is unclear who if anyone speaks for the public about the risks being assumed.
Building codes set the requirements for the initial construction elements but there are few legal requirements for the systematic maintenance of buildings or infrastructure, probably because it would involve a huge intrusion into civil and property rights — think of being mandated to replace your roof. Traditionally, redress for injuries due to lack of maintenance has had to be found in civil courts.
Cases like the Elliot Lake mall collapse and the ongoing deterioration of the Gardiner Expressway make it essential that the public understands the risks involved. Currently, most people realize this only when inquiries are held into highly publicized failures, as with the current probe into the Elliot Lake tragedy.
There are many areas of society where a cost/benefit equation involves the political and public acceptance of lost lives. One easy-to-understand example is that placing barriers on all divided roads would eliminate almost all fatal headon collisions, but the cost per life saved is such that society decides not to devote the resources necessary to achieve this end.
A recommendation to tear down the Gardiner Expressway, ravaged by time and corrosion but necessary to the life of the city, likely is a non-starter politically because of the costs involved. That may explain why negative reports about its condition were suppressed until exposed by newspaper investigations. Yet, two weeks before the collapse of the Algo Mall in Elliot Lake, the possibility that a portion of the Gardiner could fall and kill people would have seemed far more likely. Where would you have put your money?
It is abundantly clear that the Gardiner is as close to the end of its serviceability as can be rationally predicted. No one could claim surprise if a significant portion were to collapse tomorrow.
The inquiry into the Algo Mall collapse will eventually bring some realities into focus. There will be recognition that there were ways to avoid the loss of two human lives and there will be an allocation of blame.
But the fundamental lesson from what happened in Elliot Lake is that the public has a vital interest in the allocation of resources for critical public buildings and infrastructure. The collapse of the Algo Mall was an early warning: as a society, we must take a more proactive approach and not just wait for the next inevitable collapse to make remedial action more politically expedient.