All the characters are hard to relate emphatically and emotionally.
Kind of not make sense to me that they didn't jump into the water to save their family even if its just to retrieve the dead body. Did they even care in the first place about the eldest??
The younger sister also break rules by attracting attention by her act and be smug on the crime scene she made herself.
The only one who is actually careful and watchful is the grandmother.
Overall its hard to relate to the characters emotionally therefore it gets pretty bland.