Police in Wichita say a 1-year-old boy has died after being pulled from a backyard swimming pool.

KAKE-TV reports the baby’s 18-year-old mother found him unresponsive in the water around 11 a.m. Tuesday. The toddler had gone outside while the mother and five other children were sleeping.

The boy had been pulled from the pool by the time first responders arrived. He was taken to a hospital in extremely critical condition and died a few hours later.