Windows on the World was the restaurant complex on the top floors of the World Trade Center complex. More than 70 restaurant employees were killed in the attacks of 9/11.
Esquire runs a lengthy piece by Cal Fussman about Windows on the World (also see Ruth Reichl's remembrance). It talks about the seriousness of becoming a sommelier (he worked at Windows as part of a story for Esquire), his reactions to the 9/11 attacks and why it's taken him 10 years to complete the story.
Fussman's piece shows how traumatic 9/11 was for so many people, even those who didn't know a single person who perished.
The story is here.