The Curious Mystery of the Sidewalk Tombstone

You can find just about anything on the sidewalks of New York, so when John Lankenau happened upon a tombstone while walking his dog one night a few years ago, he took his grim discovery in stride. Then he did what any self-respecting citizen would do: He carted the two-and-a-half-foot-high granite marker, which weighed several hundred pounds, home for safe-keeping.

“I didn’t think it would last long there until it got vandalized or dogs urinated on it,” Mr. Lankenau recalled. “It once meant something to somebody. I just couldn’t imagine someone’s life sitting on the street.”

But a tombstone is not the sort of missing object people ordinarily claim, so putting up fliers or placing a lost-and-found notice in a newspaper did not seem to make sense. Instead, Mr. Lankenau kept it, first in the living room of his apartment on the Lower East Side, not far from where he found it, and later in the garden behind his apartment building, a tantalizing totem of urban anonymity and fleeting mortality.