Watch a lava bomb crash through the roof of this boat full of tourists

Passengers on a tour boat near Hawaii’s Kilauea volcano got to see lava a lot closer-up than they'd bargained for when a bowling ball–sized lava bomb crashed through the boat’s roof, injuring 23 of the people aboard.

Shane Turpin, the driver of the sightseeing boat, told the Associated Press that when they were about 500 yards from the Big Island's volcano, he didn’t see any explosive activity, so he motored up a little closer. Turpin estimates he was about 250 yards from the lava flowing into the ocean when the lava bomb crashed through the roof.

The size of the explosion wasn’t even clear to Turpin until he saw a video of it, taken by one of the tourists, once they were safely back on shore.

“It was immense,” Turpin told the AP. “I had no idea. We didn’t see it.”

One woman was in serious condition with a broken leg, 13 others were treated at a nearby hospital, and the rest got treatment for superficial injuries once the boat docked.

Most boats aren’t supposed to be closer than 300 meters from the point at which lava hits water, but tour boats and scientific vessels can apply for permission from the Coast Guard to get within 50 meters of lava, and Turpin’s boat was allowed to get closer than 300 meters.

The Coast Guard is investigating Monday’s incident, and is now requiring that all boats, even those that previously had permission to get closer, stay 300 meters away, the Coast Guard told VICE News.

Turpin told the Associated Press that he’d been doing this kind of work since 1983 and had never seen anything quite like this explosion.

"It was suddenly bedlam. There was screaming,” Kirk Olsen, one of the tour boat passengers, told CBS News. “You'd look on the floor and there were hot lava rocks glowing.”

READ: Hawaii’s Kilauea volcano just threw a huge ash cloud 2 miles into the sky

Since Kilauea started erupting in early May, the lava pouring from the volcano has engulfed over 700 homes in flames, according to the Hawaii County Civil Defense Agency, and the activity has become more violent in recent weeks. What started as a seeping, slow eruption, with lava moving slowly over the Big Island, has more recently been erupting with force, sending chunks of molten rock flying into the air.

The eruption has so far added 690 acres of land to the Big Island, according to the USGS. It completely filled up the beloved Kapoho Bay, a popular snorkeling site whose tide pools attract residents and tourists alike.

The lava also evaporated the island’s largest freshwater lake — within just a few hours. Green Lake, a popular swimming spot that was 200 feet deep, is now totally dried up.

In May, about two weeks after the volcano started erupting, it shot ash thousands of feet into the air, prompting evacuations and prompting official warnings to pilots to avoid the area.

Cover image: This photo provided by the Hawaii Department of Land and Natural Resources shows damage to the roof of a tour boat after an explosion sent lava flying through the roof off the Big Island of Hawaii Monday, July 16, 2018, injuring at least 23 people. The lava came from the Kilauea volcano, which has been erupting from a rural residential area since early May. (Hawaii Department of Land and Natural Resources via AP)