One of the largest and most photographed stone arches in Arches National Park in the U.S. has collapsed.
Wall Arch fell sometime late Monday or early Tuesday, though no one has reported seeing it collapse, said Paul Henderson, the park's chief of interpretation.
He said the arch, located along the popular Devils Garden Trail, was claimed by forces that will eventually destroy other arches in the park: gravity and erosion.
"They all let go after a while," he said Friday. Nevertheless, it was the first collapse major arch in the park since nearby Landscape Arch fell in 1991.
For years, Wall Arch had been a favorite stopping point for photographers. Like others, it was formed by entrada sandstone being whittled over time into its distinctive formation.
Measuring more than 33 feet tall and 71 feet across, Wall Arch ranked 12th in size among the park's estimated 2,000 arches. It was first reported and named in 1948.
Rock fall from the remaining arms of the arch has forced the closure of a portion of the trail. Henderson said it would reopen when it was deemed safe and debris had been cleared.
Officials from the National Park Service and the Utah Geological Survey visited the site Thursday, noting stress fractures in the remaining formation.