It's tall, sure, but is it a 'building'?

The careful formulation Torontonians use to describe the 1,815-foot CN Tower - "the tallest freestanding structure in the world" - diplomatically skirts the question of whether it really is a "building."

Traditionalists say it's not. A building must have floors, they insist, with offices, apartments, and some resident population, not just gaggles of tourists who take in the view and then zoom back down.

Note, too, that qualifier: "freestanding." The "tallest structure in the world" is - who would have guessed? - the 2,064-foot KTHI-TV mast in Fargo, N.D.

The mast is, however, held up by wires. The CN Tower stands very much on its own. Building or structure, though, the CN Tower is an object lesson in urban symbolism.

In fact, says Christopher Hume, art and architecture critic of the Toronto Star, the tower's value is all symbolism. "The tower represented - not a coming of age, that would make too much of it - but a ... way for Torontonians to assert themselves on a world stage.

"It was a very adolescent kind of impulse - but a very human one," he says.

The tower was completed in 1976, as Toronto was awaking to the realization, Mr. Hume says, that it had transformed itself from a gray provincial capital into a cosmopolitan metropolis. Moreover, the city's characteristic civility and reserve had turned out to be the qualities that had helped make the change possible.

"It was our moment," Hume says. "The whole city watched that day" as the tower was topped out.

Jamil Mardukhi, construction supervisor and part of the design team at NCK Engineering in Toronto, which helped build the tower, remembers it well. It was his first big job. The tower was made of continuously cast concrete, poured into a giant "slipform" that had to be moved along, and up, as the tower took shape.

Work continued 24 hours a day, seven days a week. "If there's a problem, you have to take care of it while it's moving," he says. "Day by day we were breaking records," surpassing the towers that had defined the city's skyline until then. He's still involved 23 years later. "There's always something to do there, studies, inspections. I've spent all my professional life there. "