Four children were killed and a fifth was missing after a horse-drawn buggy overturned in Kentucky during a rainstorm Wednesday afternoon, authorities said.

The search was ongoing in Bath County in the northeastern part of the state, where the horse and buggy were navigating a low-water bridge when it overturned the children and an adult into the water, Kentucky State Trooper Scott Ferrell said.

The adult was quickly rescued, he said. Four of the children had been found dead, and officials are searching for the fifth child, Ferrell said.

"Tragically, we have also had five Amish children swept away by floodwaters this evening after the heavy rain we’ve experienced today," Bath County Judge-Executive Bobby C. Rogers said on Facebook Wednesday. "I ask that you please remember these individuals, and their families in your prayers this evening, and the days ahead."

NBC affiliate WLEX of Lexington reported that authorities were called to the scene about 4:30 p.m.

The search was expected to continue through the night. Rogers said the National Guard had dedicated 50 members to the effort.