Six-year-old Darien Hicks was found without vital signs in the family's pool in Fort Erie.
It happened at home on Rose Hill Road Saturday afternoon.
The boy was taken to hospital in serious but stable condition after people started CPR before paramedics and firefighters arrived.
However, on Sunday, his father posted to a community Facebook group that his son didn't pull through.
The family says it's donating their son's organs to help others.
A Go Fund Me page has been set up to help the family with funeral costs
https://www.gofundme.com/f/i039m-honor-of-little-darien-and-his-family