Where is the two-year-old kid?

2018/ 08/ 14
Who is to blame?   The grandfather?
Is he a suspect because he was the last person that saw the kid 'go home.'  
Do you believe what the old man said?
What if he lied to the police?  He might have taken the kid somewhere.  They were heading for the beach almost 400 meters away from their house.  The kid was carried away by the waves while the old man and the kid's elder brother were hanging around.
Is it natural that we allow a two- year-old kid go home alone?  400 meters?  
The elderly should have taken the kid with him home.  Why was he left alone?