The unidentified toddler’s 54-year-old uncle and 85-year-old grandfather tried searching for him after realizing he had gone missing just after noon Thursday, according to police. They reported him missing to police at 2:18 p.m.

The toddler was then found about 20 minutes later in the Mamaroneck River, a seven-mile stream that runs through southern Westchester, according to Village of Mamaroneck Police Lt. P.J. Trujillo.

Mamaroneck EMS pronounced him dead at the scene.

Officials believe he left home with the family dog and then walked two blocks from his home, fell into the water and drowned. He was then likely carried downstream to the Hillside Avenue Bridge where he was found.

Police did not immediately provide additional details, including if the dog had turned up.

Mamaroneck Police are investigating along with the Westchester County District Attorney’s Office.