Lava Ocean Tours, the lava boat tour operator whose 23 passengers were injured Monday morning by lava bombs, had a special permit to come within 50 meters of the lava’s ocean entry point, the U.S. Coast Guard said.

But the Coast Guard yanked all special permits after the injuries Monday, and the four permitted lava boat tour companies must now remain 300 meters from the ocean entry, said Coast Guard Petty Officer 3rd Class Matthew West.

The restrictions were shortened a week ago to 50 meters from 100 meters, and Lava Ocean Tours pushed for the change, said Kanoa Jones, who owns one of the four permitted companies, Moku Nui Lava Tours.

Until Monday the eruption of Kilauea, which began May 3, had caused relatively few direct human injuries. Darryl Clinton injured his left ankle when a lava bomb hit him May 19 as he was standing on his lanai.

Most of the damage Monday was done by one lava bomb — a little larger than a basketball — that exploded into the air and onto the boat, crashing through its metal roof and landing on the passengers below. Smaller lava rocks pummeled the boat, known as Hot Spot.

Visitor Will Bryan, 38, of Portland, Ore., was aboard the boat with his girlfriend, Erin Walsh, 31, when they saw a huge cloud of black smoke and lava heading for them. It rained glowing lava rocks down on them, “like massive pieces of charcoal,” Bryan said.

“Honestly, it was terror,” he said. “You have 20 feet to hide. You’re just getting shot with lava. There was no safe spot. I got hit in my back, and my girlfriend was hit in the face.”

He said the piece that came through the roof was about a foot in diameter; he thinks it ended up breaking the femur of a young woman who was seated in the spot where it landed.

Department of Land and Natural Resources officials said the “bomb” ruptured a 1-1/2-foot-plus-diameter hole in the metal roof.

Visitor Vim Mahadevan, 48, of Sherman Oaks, Calif., was on a separate lava tour boat and had a front-row seat when he saw rocks and ash land on the Hot Spot.

“They seemed really, really close,” Mahadevan said. “We were 1,000 feet away (offshore). Those guys were much closer.”

He described the lava bomb as a fireball that went up 20 to 30 feet into the air, followed by a large plume of billowing white smoke. He estimated 48 to 50 were aboard the vessel.

The Lava Ocean Tours vessel was inside the Coast Guard’s 300-meter (328-yard) safety zone at the time of the lava explosion shortly after 6 a.m., state and county officials said.

Fire officials said the boat arrived about 500 yards offshore of the lava entry point and proceeded to get closer until it was about 200 yards from the shoreline.

The boat then turned out to sea when “an explosion occurred near the shoreline hurling hot lava rocks toward the boat and injuring several passengers,” Fire Department officials said.

The boat returned at about 7 a.m. to Wailoa Harbor in Hilo, where medics and firefighters responded.

Three people were taken by ambulance to Hilo Medical Center. Ten went to the hospital in personal vehicles, and medics treated 10 people at the scene for minor burns and abrasions, fire officials said. Two of the three passengers taken by ambulance were in stable condition. The third passenger, described to be a woman in her 20s, is in serious condition with a fractured femur.

Prior to being hit, the passengers were watching a plume of lava shooting out every 30 seconds. “It was amazing and beautiful until it wasn’t,” said Bryan.

DLNR spokesman Dan Dennison said a witness recounted seeing the lava bomb coming up out of the ocean.

Ken Rubin, professor of geology and geophysics at the University of Hawaii at Manoa, said small steam-driven explosions can occur at lava cones near the ocean’s edge, throwing out bombs of both molten and not-molten lava. “This happens right at the water’s edge, so I could see how someone standing nearby might think it came from the ocean.”

Shane Turpin, owner and captain of the Hot Spot, told The Associated Press he never saw the explosion that rained molten rocks down on his boat.

After 20 minutes in the area making passes of the lava’s ocean entry about 500 yards offshore, he didn’t see “any major explosions,” so he navigated his vessel about 250 yards from the lava, he said.

“As we were exiting the zone, all of a sudden everything around us exploded,” he said. “It was everywhere.”

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.”

His company continues to operate, and a call Monday afternoon to its reservations desk was still taking tours and telling callers its tour boat will take visitors as close as 100 yards from the lava entry point.

Turpin was fined $15,000 in June 2017 for three violations of state boating rules for using a public boat ramp without a valid permit in February 2017.

Turpin did not respond to emails and calls from the Honolulu Star-Advertiser for comment.

“This was about being at the wrong place at the wrong time,” said Toni Marie Davis, executive director of Activities & Attractions Association of Hawaii. “They were well within safety zones.”

Jones, owner of Moku Nui Lava Tours, said he and his colleagues have been avoiding the area where the accident happened. “We go way outside. It’s not like all of a sudden there’s been an eruption or an explosion. It’s been going on there for the last few weeks.”

But “it’s the first time it’s done this to a boat,” Jones said.

The Coast Guard and the state Department of Land and Natural Resources’ Division of Conservation and Resources Enforcement are investigating to determine the exact location of the vessel at the time of the explosion.

The Coast Guard implemented the safety zone surrounding the ocean entry of lava on the island’s southeast side to protect people and vessels from potential hazards of the flow.

Entry into the zone, which encompasses all waters extending 300 meters in every direction around the ocean-entry point of the lava flow, is prohibited, West said.

Honolulu Star-Advertiser reporter Allison Schaefers contributed to this story.