GRAND CANYON NATIONAL PARK, Ariz. (AP) -- Authorities searched Grand Canyon National Park on Monday for a teenager and his step-grandmother who were swept away as they tried to cross a creek during a family trip in a remote part of the park.
Two fellow hikers in their group alerted officials over the weekend by setting off an emergency GPS locator beacon in the backcountry below the canyon's North Rim, according to Chief Ranger Matt Vandzura of the National Park Service.
He said the 14-year-old boy and 62-year-old woman lost their footing and were swept away Saturday in Tapeats Creek, a tributary of the Colorado River that runs through the Arizona landmark.
The McCallie School, an all-boys school in Chattanooga, Tennessee, said one of its students, eighth-grader Jackson Standefer, and his step-grandmother were swept down the creek.
"The entire McCallie community sends its prayers to the Standefer family and all those close to Jackson as we all hope for a positive ending to this situation," the school said in a statement, which didn't name the woman.
Vandzura declined to identify the missing pair, the other hikers or their relationship to each other. He said it's too early in the investigation to determine what went wrong.
No rain or flash flooding was reported in the area, but it was not known whether the water level of the creek was higher than usual.
Creeks in the canyon often see higher water levels in the spring as snow melts, Vandzura said.
The Park Service describes conditions in the area on its website, warning that melting snow or heavy rain may make crossing the creek impossible. It also said hikers can use a "sketchy, seldom used trail" that lets them walk around the creek when the water is high, but that the path should be used only as a last resort.
Authorities say the four hikers in the group were on a different path known as Tapeats Trail.
An Arizona Department of Public Safety helicopter searched for the missing pair Saturday night, and the Park Service sent a helicopter and several ground crews to comb the area Sunday.
The Park Service resumed the search Monday with ground crews, a helicopter and a drone.