An explosion from a long-erupting volcano sent molten rock crashing through the roof of a sightseeing boat off Hawaii's Big Island, injuring 23 people on Monday.
A woman in her 20s was in serious condition with a broken thigh bone, the Hawaii County Fire Department said. Three others were in stable condition at a hospital with unspecified injuries. The rest of the passengers suffered burns, scrapes and other superficial injuries.
They were aboard a tour boat that takes visitors to see lava plunging into the ocean from an active volcano that has been vigorously shooting lava from a new vent in the ground for the past two months. The lava punctured the boat's roof, firefighters said.
Shane Turpin, the owner and captain of the vessel that was hit, said he never saw the explosion that rained molten rocks down on top of his boat.
He and his tour group had been in the area for about 20 minutes making passes of the ocean entry about 450 metres offshore, Mr Turpin said.
He did not observe "any major explosions," so he navigated his vessel closer, to about 250 yards away from the lava.
“As we were exiting the zone, all of a sudden everything around us exploded,” he said. “It was everywhere.”
Mr Turpin said he had no idea just how big the blast was until he saw video of the event later on shore. “It was immense,” he said. “I had no idea. We didn’t see it.”
Mr Turpin says that he has been observing and documenting these explosions and that this type of activity is new. There were no warning signs before the blast, he said.
“There’s something new. There’s something really new,” he said. “And I’ve been documenting them a bit.”
Mr Turpin has been navigating lava tour boats for many years and has lived on the Big Island since 1983.
He said most of the injuries were minor, but that he had just visited one woman who sustained serious injuries in the hospital.
The others in the tour group quickly pulled together and helped one another, Mr Turpin said.
"In all honesty, we definitely evaded a catastrophic event today."
Officials have warned of the danger of getting close to lava entering the ocean, saying the interaction can create clouds of acid and fine glass. Despite the hazards, several companies operate such tours. The Coast Guard said tour vessels have operated in the area going back at least 20 years.
The US Coast Guard in May instituted a safety zone where lava flows into the ocean off the Big Island. It prohibits vessels from getting closer than 300 metres from ocean-entry points.
The agency allows experienced boat operators to apply for a special license to get up to 50 metres from where lava sizzles into the sea.
The molten rock is coming from the Kilauea volcano, which has been erupting for the past 35 years. In May, its eruption entered a new phase when it began spurting lava through newly formed fissures in a residential neighbourhood.
It has destroyed more than 700 homes since then.
Officials were interviewing injured passengers at a hospital.