Palm Beach County deputies responded to the Belle Glade neighborhood shortly after noon, a sheriff’s office news release said.
A woman had been watching her 2-year-old and 3-year-old grandsons, officials said. The woman told detectives that the children had been playing in a screened-in patio in the backyard when she noticed they were no longer there. The grandmother said she searched the surrounding area for about 30 minutes before calling the sheriff's office.
As deputies searched, a sheriff's office aviation unit spotted the children in a neighbor's pool, officials said. The children were taken to a nearby hospital, where they were pronounced dead.
Officials didn't immediately identify the children. No criminal charges were reported.