Searchers found the bodies of two-year-old Nicole Payne and her three-year-old brother Jonah Monday in an algae-covered pond not far from their home in Warrenton, 100 miles east of Atlanta.

The toddlers had been the focus of a massive search since they disappeared on Saturday.

Earlier Monday Georgia Bureau of Investigation spokesman John Bankhead told reporters the search had reached a “critical stage.”

Searchers had checked the pond on Saturday, Bankhead said, but because of the heavy cover of algae on the surface, did not see the bodies.

On Monday, searchers checked again and noticed what Bankhead described as a bump in the algae cover, which turned out to be the body of the missing girl. The boy’s body was found nearby.

A road led from near the toddlers’ home to the pond, Bankhead said.

The toddlers’ mother told authorities the two children walked out of the house while she was in the bathroom.

Autopsies were ordered.