(CNN) -- Four men died after horsing around in a boat on a southern Idaho reservoir, authorities said late Monday.

The bodies of four men were found Monday evening in the American Falls Reservoir in the same area where the men had fallen into the water a day earlier, said Cpl. Leilani Morgan of the the Power County Sheriff's Department.

The search began Sunday for the four boaters after authorities received a 911 call from a child on their boat, said Power County, Idaho, Sheriff Jim Jeffries. The four men were "horsing around," he said. One man was standing up in the front of the boat and another man pushed him into the water as a joke, not realizing he could not swim, he said.

"There were enough vests for all four adult men to have them on. However, they did not have them on," Morgan said.

KIFI: Four boaters' bodies found.

The victims have been identified as 57-year-old Darrel Shappart, 26-year-old Jared Hale, his 30-year-old brother Aaron Hale and 30-year-old Stephan Verbeck, Morgan said. The men were boating on the waterway Sunday along with five children under the age of nine.

The frantic 911 call triggered a search where rescuers used boats with side-scanning sonar to locate the men in the reservoir, which is about 180 miles east-southeast of Boise.

CNN's Ashley Hayes, Greg Morrison and CNNRadio's Richard Benson contributed to this story