“My September 11th started on September 10th,” Frank Hussey said.

It has yet to end.

Mr. Hussey, who just turned 55, is one of the Tishman Construction superintendents guiding 3 World Trade Center 1,079 feet skyward. Before that, he was at 4 World Trade Center. Before that, at 1 World Trade Center. Before that, at 7 World Trade Center. Before that, he worked on emergency repairs to the Bank of New York’s data center, which was damaged on Sept. 11, 2001.

Mr. Hussey has, in other words, devoted 15 years of his life to rebuilding the trade center.

But he dates his personal involvement to the night before the attack, when he was overseeing the installation of two communication masts atop an AT&T building less than a mile north of the trade center. The next morning, he was up on the rooftop to ensure the masts had been placed securely.

“The first plane came directly over us,” Mr. Hussey recalled. “We heard the rumble. We were watching the belly of this plane in awe. Someone said, ‘This guy’s flying too low.’”