Park service says the Hōlei Sea Arch fell between 23 and 28 September

Hawai'i Volcanoes National Park said on Thursday, 2 October, that the Hōlei Sea Arch is gone. The formation, cut into a cliff of lava about 550 years old, stood roughly 90 feet, or 27 metres, on the southern coast of the Big Island. Park staff said it was still there on Wednesday, 23 September. When the park reopened on Monday, 28 September, the arch had fallen into the Pacific. The exact hour is unknown.

The park's own posts on Facebook and Instagram were blunt. "Yes, it's true. RIP Hōlei Sea Arch." Before-and-after photographs, including a 30 September frame credited to park photographer Janice Wei, show open water where the span had been. Google Maps marked the viewpoint permanently closed. Rangers asked visitors to stay off unstable cliff edges.

The storm in the gap

The five-day gap is not empty. Tropical Storm Nolo, fed by El Niño-warmed water in the Pacific, passed about 145 miles south of the Big Island on 26 September. The park was shut for the storm. Heavy rain and strong gusts hit the coast while no one was counting the arch from the official overlook. The Park Service wrote that the collapse could have come during that closure. It did not claim the storm was the sole cause. Sea arches fail by differential erosion: waves cut the base faster than the crown, and a span that has lasted centuries can drop in one tide.

The park's older visitor text had already said the arch was temporary. The formation, it noted, would eventually crumble, and other arches would appear as the cliff moved inland. That sentence was geology, not a forecast for late September. What changed on 2 October is the date range. A landmark that drawings and photographs had treated as fixed now has a last confirmed standing day, 23 September, and a first confirmed absence, 28 September.

What visitors actually lose

Hōlei was a short walk from a coastal pull-off in the national park, on the youngest of the Hawaiian islands. It was not a temple or a listed building. It was a piece of a 550-year-old lava flow that the sea had punched through. The National Park Service is a federal agency, and its confirmation is the record that matters. CNN and the New York Times both anchored their accounts on that confirmation rather than on social photographs alone.

The practical change is small and local. The overlook remains a cliff. The arch was the reason many people stopped. Rangers now have a safety problem instead of a postcard: the same erosion that dropped the span leaves an edge that can drop again. The park's request to keep back from the rim is the operational sentence. Google's "permanently closed" label will steer some drivers away. It does not close the road or the rest of the coastal trail.

For the geologic account, the useful facts are the height, the age of the flow, and the window. Ninety feet of lava rock, cut from a flow about 550 years old, present on 23 September, absent on 28 September, with Nolo 145 miles south on the 26th. The park has not published a tide, a wave height or a seismic reading for the hour of the fall. Until it does, the collapse is dated to a closure, not to a measured impact. The next arch, the old sign said, will be cut as the cliff retreats. That one does not yet have a name.