But, an alligator gets to be pretty big after a while, and a New York apartment is no place to keep one.  So, when the little critters started growing, people began flushing them down their toilets.

Alligators are used to living in water, so the flush didn't kill them.  A lot of them survived the trips through the pipes and began living in the sewers of New York.

And, they began to breed down there.  Pretty soon, there was an entire colony of alligators, all of them albinos since they never got into the sun.

A lot of sewer workers have been lost down there, probably to the alligators.  That's why the City of New York has to pay sewer workers so much.  It's more dangerous than in any other city on earth.