FLAGSTAFF, Ariz. (AP) — A major flash flood at the Grand Canyon forced the evacuation of dozens of people and swept large boulders, metal structures and other debris into the Colorado River that runs through it, the National Park Service said.The flooding in Bright Angel Creek, which flows into the river, happened Saturday afternoon. Torrents of water wiped out footbridges over the creek and significantly altered the landscape, widening the creek bed and creating what appeared to be a new river rapid. The park service said it was seeking information about more than 20 people who may be missing or unaccounted for after the flood and asked anyone with details about people hiking or camping in the area to get in touch. It said it was working with the Arizona Department of Public Safety to continue evacuations Sunday.“This is a reminder of what a dynamic and active landscape Grand Canyon is,” said Jack Schmidt, director of the Center for Colorado River Studies at Utah State University.

Popular tourist spots including the Bright Angel Campground, Phantom Ranch and parts of the North Kaibab trail remained closed on Sunday while park officials surveyed the damage, the park said. Rafting trips on the Colorado River also have been halted for now.More than 60 people were evacuated from Phantom Ranch, which has a historic canteen and dorms, and is a common spot for rafters to get off and on the river. More evacuations were planned Sunday, the park said. No injuries have been reported.