Several hikers trapped in a canyon in Utah's Zion National Park have died in a flash flood, according to the New York Post.

A group of seven hikers were trapped in a narrow canyon Wednesday, said officials. At least six have died. The slot canyon where they were hiking is several hundred feet deep. Quick rain flooded the narrow space with rapid water and debris.

Search and rescue teams have been unable to enter Keyhole Canyon in order to find the still-missing hiker because of flooding dangers. The group received a permit to hike in the area Monday morning, several hours before the canyons were closed due to flood warnings for that afternoon.

The same flood killed at least 12 other people living south of the park. One boy is still missing from a group of 16 who were traveling in two cars Monday when floodwaters took control of both vehicles. The Utah National Guard has been deployed with a group of searchers who are trying to find him, according to the Albuquerque Journal.

There was no way to reach the group of hikers to let them know flood waters were on the horizon. "Ninety percent of Zion is wilderness... It is not possible to contact everyone," said Park Ranger Therese Picard, according to the New York Daily News.

The storm unleashed more than a half-inch of rain in less than 60 minutes. Sgt. Steve Arthur, 58, was one of the first deceased hikers to be identified. He worked in the sheriff's department in Ventura County, Calif.

"That little bit of rain can turn what was a very comfortable daylong excursion into a horror story, literally in a split-second... There's no escape routes," said canyoneering expert Steve Allen, reported the New York Daily News reported.