Maybe they only meant it figuratively. Like if you asked someone about the sign, they might respond, "Oh, well what we're trying to say is that you don't have to literally leave them in the station per se, or on the floor of the station, but rather, hand them to another fireman who is in the station and will make sure they are kept in a safe place while you're out shopping."

There's an idea. perhaps "station" is what the firemen call the hollowed-out fiberglass rock sitting in the bushes.

Careful, Brian: you start fining the FDNY and they're likely to throw a chair at your head and leave you in a medically-induced coma. (Especially if the firehouse in question is on Staten Island.)

With reference to your fine, "cannot" is one word, not two.

With reference to the "medically-induced coma," one should not use a hyphen after an adverb that ends in -ly. See, for example, http://www.bartleby.com/64/pages/page255.html

...just doing my part as Grammar Cop wanna-be.

I had a similar question about a sign on a DQ doorway warning about possible peanuts in their products. The whole message was in quotes, which made me giggle.

I later learned that years ago when the capacity for bold faced type was unavailable, quotation marks were used to emphasize words. This may be a throwback to those days. It still looks odd to the modern eye - especially since they managed to underline the word on the sign - but it may explain the origin.