How should I get rid of it, if at all?

I just accidently slipped on the floor and I think I killed my sister's dog when I landed on it (it is/was a Lhasa Apso). I am quite a heavy guy so when I landed on it I heard a distinct cracking noise and now it is not breathing or moving. Should I burying it in the back yard with the other pets and tell her it ran away?