A tsunami advisory has been issued for the West Coast after an underwater volcano erupted near the Pacific nation of Tonga on Saturday (Jan. 15).

The volcanic eruption sent a cloud of ash and gas steam into the air. Waves traveled across the shoreline of Nuku’alofa, Tonga’s capital, on Saturday, pouring onto coastal roads and flooding properties. According to CNN, the Hunga-Tonga-Hunga-Ha’apai volcano first erupted on Friday (Jan. 14). The eruption sent a pillar of ash 12.4 miles into the air. A second eruption hit on Saturday at 5:26 p.m. local time.

“We don’t issue an advisory for this length of coastline as we’ve done — I’m not sure when the last time was — but it really isn’t an everyday experience,” Dave Snider, tsunami warning coordinator for the National Tsunami Warning Center in Alaska, said. “I hope that elevates the importance and severity for our citizens.”

Snider said the waves that were already washing ashore in Hawaii were just under the standards for a more severe tsunami warning. “The important thing here is the first wave may not be the largest. We could see this play out for several hours,” he added. “It looks like everything will stay below the warning level but it’s difficult to predict because this is a volcanic eruption and we’re set up to measure earthquake or seismic-driven sea waves.”

Jese Tuisinu, a television reporter at Fiji One, posted a video on social media that showed people trying to escape in their vehicles from the large waves that were washing ashore. “It is literally dark in parts of Tonga and people are rushing to safety following the eruption,” he wrote in another tweet.

A tsunami advisory is also in effect for Hawaii and Alaska. The National Weather Service Seattle has urged people to use caution along the U.S. Pacific Coast. “Move off the beach and out of harbors and marinas in these areas,” the agency tweeted.