A “lava bomb” crashed onto a roof of a tourist boat in Hawaii on Monday, injuring 23 people. The Honolulu Star Advertiser reports that the molten rock was sent through the air from an explosion close to the area where lava was oozing into the ocean. The lava then “punctured” the roof of the Lava Ocean Tours boat. A young woman was seriously injured with a broken thigh bone, and 11 others were transported to a local hospital. Other passengers were treated on site for “minor burns and abrasions.” Shane Turpin, the captain of the boat, said the explosion occurred while they were “were exiting” the lava-flowing region. “All of a sudden everything around us exploded,” he said. “[The explosion] was immense… I had no idea. We didn’t see it.” Hawaii has been dealing with the continuously erupting Kilauea volcano, which has caused immense property damage and forced people to evacuate earlier this year.