Oh my god.
So
The whole plot is something like :Someone brain washed all the kids to murder their parents/guardians
and the whole country or atleast the selected area is killing their parents just like they were instructed to.
Well why i believe its something like brainwashing?
Because every kid that is running away has burned their houses in the same fashion as well (probably)
There's no reason for the children to burn their parents.
The author drawing that simply as shock value. It's never explained, nothing of worth was in this one shot.
It would be like if you drew someone slaughtering a cow.