PRICE, Utah — A 5-year-old boy pinned under his family's sport-utility vehicle during a flash flood died Tuesday, and searchers resumed the hunt for the body of his 1-year-old brother who was swept away in the same storm.

Levi Seal died at Primary Children's Medical Center in Salt Lake City, where he had been in critical condition since his rescue Sunday, great-grandfather Floyd Seal said.

The Seal family's 1980 Ford Bronco was taken nearly a mile downstream by a 20-foot wall of water caused by a thunderstorm in the Garley Wash area, about 120 miles south of Salt Lake City.

Josh and Cortney Seal grabbed their 3-year-old daughter, Brookland, from the SUV. Levi was later rescued while trapped under the Bronco, Carbon County sheriff's Capt. Guy Adams said.

Searchers found baby clothes Monday, but the body of the youngest child, Jaydan, still had not been recovered, he said.

"The terrain is just killing us. We're relying a lot on cadaver dogs," Adams said. "We just don't know how far the body's been washed downstream."

He said "it was just chaos" when the wall of water hit the Seal family.

Tom Robertson was knocked off an all-terrain vehicle during the same flood. He said Cortney Seal was caked in mud and pleading for assistance.

"She was screaming, 'Help. Help. ... My babies went down the river,"' Robertson told The Salt Lake Tribune.