Hawaii's iconic 550-year-old Hōlei Sea Arch collapses

Hawaii's famous Hōlei Sea Arch, a 90-foot-tall (27.4m) lava rock structure that formed about 550 years ago, has collapsed into the Pacific Ocean.

The collapse's exact time is not known. The arch was still projecting into the water from the coast of Volcanoes National Park on 23 September, but was gone by 27 September, the National Park Service (NPS) said.

"The coastline flanking the sea arch has shown signs of instability for years," NPS, which warned in 2021 that the arch would eventually crumble, said in a statement.

Located at the end of Chain of Craters Road on the island of Hawaii, also called "the big island", the formation was a popular - and heavily photographed - tourist destination.

The arch is believed to have fallen when the park was temporarily closed during Tropical Storm Nolo last weekend.

The park service said earthquakes during the 2018 Kīlauea volcano eruption and summit collapse had damaged the cliffs near the arch.

Its ultimate collapse marks "the latest transformation of the park's remote and rugged coastline".

In January 2020, new cracks and instability in the cliffs led the park to close the original arch viewing area, and a few months later, a new viewing area opened at a safer distance, NPS said.

Waves from a tropical storm later that year broke off a chunk of rock from the bottom of the arch.

"This formation is beautiful, but temporary, and has a limited life span," the park service said in 2021. "The sea arch will eventually crumble into the sea. However, others will replace it as the cliff slowly migrates inland."

Thousands of people have liked and commented on the NPS social media post about the arch's collapse, including sharing their memories of visiting the arch and posting photos of it.

"Nothing and no one is here forever," one Facebook user commented. "Millions of years from now the sun will die. Appreciate the good, the beauty, now."