I think i killed my neighbours dog?

i was doing some work at the back of my shed and i chucked a load of tiles down in between the garage and the neighbours garage ally thing and i heard a yelp, i havent lifted them up as they are heavy but im pretty sure they landed on something, should i tell my neighbours or just hide it and make them think its lost instead of dead as that would be better as they have a kid and i dont want to be the evil guy who killed his dog