By Mike DeNardo

PHILADELPHIA (CBS) — The structural steel-work is now finished, as construction continues at Philadelphia’s tallest building.

Credit: (KYW)

Credit: (KYW)

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Wearing a hard hat, Comcast chairman Brian Roberts added his signature to the steel beam headed to the top of the new Comcast Technology Center at 18th and Arch – now the tallest skyscraper in Philadelphia.

“It really is the conclusion of the structural steel in the building,” said John Gattuso, who is the regional director for the developer at Liberty Property Trust. “We have a little but more glass to place on the lantern that caps this building at 1,121 feet.”

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Comcast held a thank-you lunch catered by chef Greg Vernick for the 1,100 construction workers at what Roberts called a “transformational” building.

“There’s a sense of pride on this job,” he said. “I come over here a lot.  I’ve been here every week since we started and I think there’s something magical happening and they know it.”

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The building opens in phases, over the next year.