Apollo Manga has a good list of Second Life events memorializing 9/11, including a pointer to the reflecting pool pictured above. It's the creation of Liam Kanno (who I wrote about a couple years ago), in real life a New York ad executive who lived near Ground Zero, but after the terror attacks, joined a monastery and created the Second Life site, as part of his healing process. [SLurl teleport at this link]
Liam's memorial site is where I just met Mark Benelli, the firefighter featured above. He describes himself as a firefighter in real life, based in Germany. He doesn't know any brethren based in New York, but he wore his uniform and visited the memorial site, to pay tribute to their valor on that day. "I would have done the same," he tells me. "That's why I'm here... and because of all the other people."