HANKSVILLE, Utah (AP) — Sheriff's officials say flash flooding in a Utah canyon has killed one person.

The Emery County Sheriff's Office says at least 21 others escaped the flooding in Little Wildhorse Canyon on Monday. It believes other hikers are still missing based on the number of vehicles parked at the trailhead.

A search involving various agencies and helicopters was launched to find them.

The sheriff's office says that the National Weather Service reported flooding hit after an isolated thunderstorm crossed nearby Goblin Valley State Park and forecasters predicted that nickle-sized hail was possible.