A sudden volcanic eruption sent shockwaves—literally and figuratively—through one of Iceland’s most famous tourist destinations early Wednesday, forcing the evacuation of hundreds of visitors under the cover of darkness.

Just after 1 a.m. local time, the Sundhnúkur volcano exploded to life, tearing open a 1.2-mile-long fissure and spewing lava and toxic gases into the air near the Reykjanes Peninsula. The eruption triggered an emergency evacuation of the iconic Blue Lagoon spa—a bucket-list destination for many Americans—and a nearby campground in the town of Grindavík.

“There was a deep rumble, like a freight train rolling through the earth,” said Maria Chen, a tourist from California who was soaking in the lagoon when the alert came. “Then the staff rushed in and told everyone to evacuate immediately. It felt surreal.”Roughly 200 guests were staying at the spa at the time and were quickly relocated to hotels farther from the danger zone. Authorities confirmed that no injuries were reported and all individuals were accounted for.

While no structures have been damaged so far, residents in nearby towns—including Vogar and Reykjanesbær—were ordered to seal their homes tight as a noxious gas cloud drifted across the region.

Icelandic state media warned of potential sulfur dioxide exposure, which can irritate the lungs and eyes. Locals were advised to avoid outdoor activities and stay tuned for updates.

Grindavík, already no stranger to disaster, has endured a string of volcanic scares since November 2023, when dormant systems beneath the region unexpectedly reawakened after 800 years of silence. Entire neighborhoods were previously evacuated that winter, and some homes were even damaged by ground fissures and tremors.

Experts say this latest eruption shows no signs of slowing down. Lava continues to pour southeast from the new fissure, and geologists are closely monitoring for further seismic activity.

Iceland sits directly on the Mid-Atlantic Ridge, where two massive tectonic plates are slowly pulling apart. That means eruptions here aren’t just a possibility—they’re expected.

Still, for many caught in the latest blast, the reality was jarring.

“We came here to relax,” said an American couple from Florida, who had just checked into the spa that evening. “Instead, we got front-row seats to a natural disaster.”

Officials have not released a full list of nationalities among those evacuated, but the Blue Lagoon remains one of Iceland’s biggest draws for international travelers, particularly Americans.

As of Wednesday afternoon, the spa and surrounding area remain closed indefinitely. Scientists warn that the situation remains highly volatile—and this could just be the beginning.