Kittens underground!

I was just at the Franklin Avenue subway station waiting for the northbound shuttle a little while ago when I saw out of the corner of my eye something gray moving near the tracks on the other side. Of course I assumed it was going to be a rat, but it was a teeny, teeny kitten! Then I noticed the mama cat poking around a little further away, and soon two more kittens -- these two were both orange -- scurried out. They played around for a couple of minutes and then all disappeared from view under the edge of the platform. It looks like they have a nest just beneath the bench on the southbound platform side.

That hardly seems like a safe place for them to be, eh? Would this be a job for the TNR folks, or is there someone else I should call? I hate to think about any of those kittens getting squished by a train.