Hawaii's 550-year-old Holei Sea Arch collapses into Pacific Ocean during tropical storm

The collapse of a 550-year-old formation

Hawaii Volcanoes National Park confirmed that the Holei Sea Arch collapsed into the Pacific Ocean in late September 2026. The 90-foot-tall (27.4-meter) volcanic structure stood at the southern terminus of Chain of Craters Road on the Big Island. The rock formation had served as one of the park's most visited and photographed coastal features. Park records indicate the formation was standing on 23 September when gates were shut due to severe weather, but was gone by the night of 27 September. The exact hour of the collapse is unknown because park grounds were temporarily closed. Park officials posted before-and-after photos of the shoreline on social media confirming the loss, while Google Maps updated the site's status to permanently closed.

Environmental degradation and cliff fractures

The arch was carved into an ancient lava flow from roughly 550 years ago through differential wave erosion. The structure took its name from Holei, an endemic plant species belonging to the milkweed family. In 2014, geologists documented the ongoing breakdown of the pillar as waves battered the base.

The arch formed in ancient lava flows by removing rock along cracks and weaker rocks. It will not be here for ever. Every day the ocean crashes against the pillar of the arch, eroding it a little more. One day, it will be gone.

Instability worsened in 2018 when earthquakes accompanying the Kilauea volcano eruption and summit collapse fractured the surrounding cliffs. In January 2020, park managers detected fresh cracks along the edge, shuttering the original viewing platform and building a replacement platform further back three months later. High surf from Tropical Storm Darby sheared another piece of rock from the arch base later that year.

Pacific storms and El Nino conditions

The final collapse coincided with Tropical Storm Nolo, which tracked approximately 145 miles south of the Big Island on 26 September. Fuelled by El Nino-warmed ocean waters, Nolo intensified into a hurricane on 24 September and generated heavy rainfall and strong wind gusts across Hawaii. The system was the third named storm to strike the archipelago within two months. Hawaii had already endured Hurricane Lala in August and Hurricane Lowell in early September, both of which flooded roads, toppled trees, and disrupted electrical grids.

Visitor safety and park assessments

Park authorities reiterated that sea arches are inherently temporary structures that succumb to coastal retreat. In 2021, the agency published an advisory detailing the expected life cycle of the formation.

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

Following the collapse, park officials issued safety warnings after members of the public crossed safety barriers to photograph the site. Rangers instructed visitors to avoid the fractured coastal cliffs, where ongoing erosion poses severe fall risks. The event followed similar geological losses abroad, including the February collapse of the Lover's Arch rock formation on Italy's Puglia coast.