Oakridge Ridge North police say the boy's grandparents were home at the time of the tragedy and so was the boy's father.
The boy was taken to Memorial Hermann The Woodlands Hospital where he was pronounced dead.
Police say the mother lives in another state and was not there at the time of the drowning.
Officers are still working this investigation. At this time no one faces any charges.
It's the second drowning in the Houston area in the last 24 hours. Just last night, another child died after he was also found in a pool. Investigators say the 5-year-old boy was found underwater at the pool at the La Jolla on the lake apartments off Windmill Lakes in southeast Houston.
He was rushed to the hospital where he was pronounced dead. His name hasn't been released.