Sometimes the simplest memorials are the most moving.
Lawrence T. Stack, an FDNY commander in charge of a safety battalion that investigated on-duty deaths, died on Sept. 11, 2001 when the north tower of the World Trade Center collapsed.
Long Island Newsday reports that Stack, a 33-year veteran, had been pinned under rubble when the south tower fell, but had broken free and continued rescue efforts. According to eyewitness accounts, he and another fire chief were rescuing a man who had severed his Achilles tendon when the second tower fell, killing all three men.
In this photo, posted to Reddit on the 11th anniversary of the attacks, a simple message of remembrance marks a beam high atop One World Trade Center.
The message reads: "In memory of Lawrence T. Stack, FDNY Chief, Battalion 50."
The effect was not lost on members of the social news community, who commented on the memorial's fittingness.
"It'd be cool if they had done [that] for every I-Beam and support -- write a bunch of names in so that the building itself is made up, symbolically, of those that died on that site on 9/11," user "WhatamIwaitingfor" wrote. "A phoenix from the ashes."
In August, a steel beam with a signature and message from President Barack Obama and the first lady, as well as signatures of police officers and construction workers, was lifted into place at the top of the 104-story building. In 2006, families of 9/11 victims signed a beam at the base of the tower, the New York Times reports.