injured black and white cat spotted on corner of prospect ave. and 6th ave.

i saw a black and white tuxedo cat in the fenced-in lawn area of the building on the northwest corner of prospect ave. and 6th ave. around 3:00 p.m. today. it was walking with its right hind leg held up, and it was definitely hurt, but there was no way for me to get to it, and i had a dog with me, so of course i couldn't coax it over to me. it was wearing a collar with a little bell on it, so i assume it belongs to someone; the collar might have been pink, but i'm really not sure about that. i didn't know what to do other than try to put the word out, but i felt absolutely terrible leaving it. i hope someone is able to find it and help it!