An 18-month-old boy has died after he drowned in a pool in Yulee, Florida, the Nassau County Sheriff's Office said.

Sheriff Bill Leeper said deputies were called out around 11 a.m. in response to a boy found unresponsive and face down in a pool on Lents Road. The police report said the boy was taken out of the pool by the time deputies arrived, but he wasn't breathing and his skin was bluish purple.

Deputies tried performing CPR on the child and transported him to the hospital where he was declared dead.

Leeper said a 16-year-old girl was babysitting five children at the time. They believed the 18-month-old crawled through the pet door and into the pool. The teen found the boy unresponsive in the pool, Leeper said.

The Florida Department of Children and Families is now investigating the case, along with NCSO.