Tsunami from the eruption of the Hunga Tonga volcano across the Pacific Ocean.

A tsunami has hit Tonga’s largest island, Tongatapu, and reportedly sent waves flooding into the capital after an underwater volcano in the South Pacific exploded in a violent eruption on Saturday, sending a cloud of ash and gas steam into the air. A tsunami warning has been issued for the islands of Tonga and parts of Japan. Tsunami advisories have also been issued for New Zealand’s North Island and the west coast of the United States from California to Alaska, as well as Canada’s British Columbia. The first waves had already been felt on the US West Coast as of early Saturday morning, Dave Snider, the tsunami warning coordinator at the National Weather Service’s National Tsunami Warning Center in Palmer, Alaska, told CNN.