A prop Alligator going into a NYC Sewer Drain for a History Channel promo in 2011. (Getty)

This morning CityRoom reported that four years ago one Michael Miscione declared today Alligators in the Sewers Day. But any diehard urban legend obsessive knows that Alligators in the Sewers Day is February 9th, this coming Monday, and that it was declared so by Miscione and then-Manhattan Borough President Scott Stringer five years ago. Anyway, plan your celebrations accordingly.

Miscione is celebrating tonight, however—the Manhattan Borough Historian will be at Hunter College to look back on the February 9th, 1935 sighting of a gator in Harlem. The next day, the NY Times reported:

The youthful residents of East 123d Street, near the murky Harlem River, were having a rather grand time at dusk yesterday shoveling the last of the recent snow into a gaping manhole.

Salvatore Condulucci, 16 years old, of 419 East 123d Street, was assigned to the rim. His comrades would heap blackened slush near him, and he, carefully observing the sewer's capacity, would give the last fine flick to each mound.

Suddenly, there were signs of clogging ten feet below, where the manhole drop merged with the dark conduit leading to the river. Salvatore yelled: "Hey, you guys, wait a minute," and got down on his knees to see what was the trouble.

What he saw, in the thickening dusk, almost caused him to topple into the icy cavern. For the jagged surface of the ice blockade below was moving; and something black was breaking through. Salvatore's eyes widened; then he managed to leap to his feet and call his friends.

"Honest, it's an alligator!" he exploded.

This year marks the 80th anniversary of the event, which had its skeptics, but nevertheless helped start one of the best urban legends. Below, please enjoy Hill Street Blues "Gatorbait" (Season 1, Episode 10):