They put them in a stairwell, but this officer didn't hand the dog off to anyone, he just tossed it on the ground and left it to try to get on the moving bus. Hopefully someone else picked up the dog and took it to the stairwell, for later pick-up by animal rescue workers. I hope the dog that has been found and is believed to be Snowball, really is.
It is sad because animals/pets in all their innocence have absolutely no understanding of what is happening.