NEW YORK (AP) — On most construction projects, workers are discouraged from signing or otherwise scrawling on the iron and concrete. At the skyscraper rising at ground zero, though, they're being invited to leave messages for the ages.

"Freedom Forever. WTC 9/11" is scrawled on a beam near the top of the gleaming, 104-story One World Trade Center. "Change is from within" is on a beam on the roof. Another reads: "God Bless the workers & inhabitants of this bldg."

One of the last pieces of steel hoisted up last year sits near a precarious edge. The message on it reads: "We remember. We rebuild. We come back stronger!" It is signed by a visitor to the site last year — President Barack Obama.

The words on beams, walls and stairwells of the skyscraper that replaces the twin towers lost on Sept. 11, 2001, form the graffiti of defiance and rebirth, what ironworker supervisor Kevin Murphy calls "things from the heart." They're remembrances of the 2,700 people who died, and testaments to the hope that rose from a shattered morning.

"This is not just any construction site, this is a special place for these guys," says Murphy of the 1,000 men and some women who work in the building at any given time, 24 hours a day, seven days a week.

"Everyone here wants to be here, they want to put this building up," Murphy says. "They're part of the redemption."

On a frigid, windy winter day, with the 9/11 memorial fountain straight below and the Statue of Liberty in the distance, Murphy supervised a crew of men guiding the first piece of the steel spire that will top out the building at a dizzying 1,776 feet — the tallest in the Western Hemisphere.

In the rooftop iron scaffolding for the spire, 105 floors up, a beam pays homage to Lillian Frederick, a 46-year-old administrative assistant who died on the 105th floor of the south tower, pierced by a terrorist-hijacked airliner.

A popular Spanish phrase is penned next to two names on one concrete pillar: "Te Amo Tres Metros Sobre el Cielo," meaning, "I love you three steps above heaven."

Some beams are almost completely covered in a spaghetti-like jumble of doodled hearts and flowers, loopy cursives and blaring capitals. Many want to simply mark their presence: "Henry Wynn/Plumbers Local (hash)1/Sheepshead Bay/Never Forget!"

Families of victims invited to go up left names and comments too, as did firefighters and police officers who were first responders. "R.I.P. Fanny Espinoza, 9-11-01" reads a typical remembrance signed by several family members of a Cantor-Fitzgerald employee. Continued...