A week ago, 19-year-old Sydney Rector of the Bronx went to a music store in Midtown Manhattan with her boyfriend, Stevin Tyska. When they left, they were playing around in a tunnel between 48th and 47th streets — and that's where they stumbled across a 66-year-old dog tag. "It's a plastic tunnel and above you there's a waterfall," Rector tells NPR's Robert Siegel. "So you see the water falling on you; it's pretty cool. We were walking through, dancing around, being stupid, and my boyfriend saw something sticking out. And we always just mess with stuff, you know. We saw...