Dear Editor, Mr. Love contends in his epistle that WTC 7 fell due to weakened structural steel ["Postmarks," Sept. 1]. However, we have many instances of skyscrapers burning for much longer, in a much more severe fashion without ever collapsing. In 2004, the tallest skyscraper in Caracas, Venezuela, burned for more than 17 hours (more than twice as long as WTC 7). The fires spread over 26 floors. Firefighters were unable to reach the upper floors, which burned uncontrollably, and sprinkler systems failed. That building still stands to this day. While he says that it is ridiculous to assert that the WTC buildings are the only skyscrapers in modern times to collapse due to fire, a studious individual will find that, indeed, it is true. There is no precedent for a burning steel-framed building to collapse, even in extreme situations. While the extenuating circumstances of the twin towers makes them more likely victims of "pancaking," the collapse of WTC 7 is poorly explained, and utterly ignored in the 9/11 Commission Report (not a single mention), along with many other important questions. Did the engineers who designed WTC 7 not theorize that perhaps a fire would burn for several hours? Did they not take steps to prevent structural collapse in this situation? Forgive me, but any skyscraper that crumbles to dust after a not-very-dramatic or widespread fire (compared to many in recent memory) isn't worth its weight in rubble. Any engineer who designed such a building is a fraud. I welcome the input of anyone who can tell us of another steel-framed skyscraper, anywhere, that collapsed due to a fire of any size, severity, or duration. Anyone?