Ground zero: A selfie stop for some. A cemetery for others.

NEW YORK (AP) — Twenty years after terrorists flew two planes into the World Trade Center, the memorial at ground zero is like a lot of city tourist sites. Visitors from around the world come and go, snap selfies and then leave. But for those who live and work close to the memorial, the site is both a part of their daily routine and hallowed ground. A police officer guarding the memorial still occasionally feels overcome with emotion. A neighborhood resident since before the attacks tries to convey the sense of loss to visitors. A maintenance worker in the reflecting pools recalls victims he knew personally.