The men and women who build New York City's skyscrapers aren't a soft bunch, but even the toughest were unprepared for the job that took over their lives in September of 2001.
While Americans grieved the 9/11 attacks and U.S. troops went to war in Afghanistan, another army, one made up of ironworkers, heavy equipment operators and mason tenders, toiled day and night to clear away the destruction of the World Trade Center's twin towers in lower Manhattan and recover the bodies of the dead.
In just 8½ months, an estimated 1.8 million tons of twisted steel and pulverized concrete were painstakingly removed, transforming a mountainous pile into a 16-acre hole that became known as The Pit.
By Memorial Day, it was all but over. The day after the holiday, workers cut down the last column of steel still standing at the site.
"I remember coming out of the hole," said ironworker Danny Doyle, one of the men to wield the cutting torch. "And it was Fleet Week, and all the sailors and the enlisted men had come down, and they lined the whole ramp on both sides, and as we were leaving ... they were all saluting us."
Monday marks the ninth anniversary of the formal end of the recovery operation, which concluded in 2002 with a ceremony to remove the 65-ton column that Doyle and others had cut down. The steel, covered in a black shroud, was driven up a long ramp to street level.
"It was closure, really, more or less," he said. "That was it for us. For me, anyway. From what I saw down there, and to see it finally empty. I thought, 'That's good enough for me.' It was time to move on."
In the end, closure — that state of grace people always seem to seek after tragedy — was elusive, both for the project and the workers themselves.
Construction workers would continue finding bones and other fragments of human remains for years, hidden in adjacent buildings and beneath manholes. Demolition work on one heavily damaged tower at the edge of the site, the former Deutsche Bank building, didn't end until this year. Two firefighters died in 2007 when that tower caught fire.
And, as the years wore on, it became apparent that the men and women who cleared the site had given more than their back-breaking labor.
The long hours of the job had taken fathers away from their children and strained marriages. Many of the workers, especially those there early on, had inhaled or ingested a lot of dust and smoke. Some are still suffering from the asthma-like respiratory problems and other health issues that plague so many people who toiled at ground zero.
Then, there are the memories to deal with.
When people from the construction trades first began reporting to the site almost immediately after the attacks, they assumed they were there on a rescue mission.
"In the very beginning, let's face it, everyone was trying to find someone," said Robert Walsh, business manager of Ironworkers Local 40.
It didn't take long, though, for the realization to set in that there would be no more survivors. Hope gave way to the grim process of recovering what was left of the dead, all while untangling a complicated pile of steel that, if picked apart incorrectly, could have shifted, collapsed and killed someone.
Doyle's days sometimes began with a trip to a spot that once held an evacuation stairwell for the north tower, one they knew would have been filled with firefighters when the building collapsed.
"You knew they were all in the stairway. You kind of had an idea where they were. We'd find a couple of bodies. We'd locate them, and then tell the fireman who was in charge. That was pretty much the job," he said. "You had to keep your emotions in check. And, listen, there were a lot of guys who just couldn't handle it. It got to the point where they said, 'That's it, I'm done.'"
In the evenings, after days that sometimes lasted 16 hours, he would come home to his wife, pleading for news of whether they had found the body of a missing firefighter friend.
"Yeah, it drained you," Doyle said. "Was it the hardest thing I ever did? I'd say you're goddamn right it was."
A study published in the American Journal of Psychiatry in 2007 found that nearly 18 percent of the construction and engineering work force at ground zero was still suffering from post-traumatic stress disorder a year or two after the cleanup had ended.
When spring came, and the main cleanup was over, city and state officials marked the occasion with several ceremonies, including the final one on May 30, 2002, in which workers trucked out the column and carried away an empty stretcher draped with an American flag to symbolize the missing. There were bells, bagpipes and tears for the dead.
St. Paul's Chapel, a neighborhood church that had served a half million hot meals to the workers during the recovery operation, held its last service and then closed for its first cleaning since the attacks.
Mayor Michael Bloomberg, then new on the job, was among those who recognized the importance of the accomplishment.
"It was five months into my first term, and I remember feeling an enormous sense of gratitude and pride in the resolve of our city and our nation and the spirit and selflessness of New Yorkers," Bloomberg said in statement Friday. "The fact that it was completed faster than expected is a tribute to the men and women who put their lives on hold to put in long days at the site."
Thoughts then were just beginning to turn to what would be built next at the site; the urgency and speed of the initial recovery wasn't matched in the following years.
Building any new skyscraper in New York City is a complicated affair, and this project was fraught with the additional complications, including sorting out who would pay for what in the multibillion-dollar rebuilding campaign.
"It took a long time to really get started again," said Walsh, the manager at the ironworkers union. "We all thought it was a shame that nothing was going on for so long."
Today, though, work is again proceeding at a terrific pace. The landmark tower at the site, One World Trade Center, is now 66 stories high, and scheduled to be completed in 2013, topping out at 1,776 feet.
Along with thousands of other workers, more than 400 members of the ironworkers local are once again toiling at the site. Those crews include many of the workers who cleared the site of rubble, and are now there to finish the job they started almost a decade ago.