The ancient Double Arch rock formation at Glen Canyon National Recreation Area (GCNRA) in southern Utah collapsed last Thursday, the National Park Service has revealed.
Witnesses have said that people cleared out of the water before the tumble at the popular hiking spot, and no one was hurt.
"This event serves as a reminder of our responsibility and need to protect the mineral resources surrounding Lake Powell,” said Glen Canyon National Recreation Area superintendent Michelle Kerns.
“These features have a life span that can be influenced or damaged by manmade interventions. While we don’t know what caused this collapse, we will continue to maintain our resource protection efforts on Lake Powell for future generations to enjoy.”
The rocks, which were 190 million years old, were made of sandstone and park rangers have said that that changing water levels and wind and rain erosion may have contributed to the collapse.