Well....I've seen such happening in my neighborhood, where the tenants were robbed and neither the landlord nor any neighbor heard anything, though all the houses are row houses and have common walls. One can listen everything clearly in the next house, but no one heard anything and they robbed them for Rs. 3 lac about 4 years ago.
There is nothing to not believe. One should become a parent to understand the trauma of losing a child. Once you understand that, you'll never blame parents for this act.