9/11's first recorded casualty was Father Mychal Judge, a gay Franciscan fire chaplain who ran to help with the firefighters he served:

As it happened, French documentary filmmakers were inside the North tower. Their camera captured some of the last moments of Mychal Judge's life. In the film, says his friend, Father Michael Duffy, you can see the priest standing by the plate glass window, watching the bodies fall on the patio outside. "And if you look closely at that film, you'll see his lips moving," Duffy says. "Now, for those of us who know him, he wasn't one that talked to himself. He was praying. And absolving people as they fell to their death."

Tony Adams concentrates on the Church's reaction:

Among the victims and heroes of 9/11 were many other gay people who have been claimed and memorialized and honored by their families, friends and communities. Although a documentary film has been made about the extraordinary priesthood of Father Judge, and a section of West 31st Street has been renamed for him, The Roman Catholic Church has turned its back on all requests to initiate the process of making him an official saint of the church. A gay priest who ministers to gay people and is not heavy handed about gay sex is an inconvenience and a source of anxiety for the Catholic hierarchy who have redesigned their scrutiny of candidates for the priesthood to discourage and weed out men like Mychal Judge.

More remembrances of Judge here, here, and here.