At least 13 people on a Lava Ocean Tours vessel were injured this morning after an explosion sent lava through the roof of the boat's passenger cabin. Officers from the DLNR Division of Conservation and Resources Enforcement (DOCARE) along with the Hawai'i County Police Dept. are investigating the incident.
Hawaii DLNR
At least 13 people on a Lava Ocean Tours vessel were injured this morning after an explosion sent lava through the roof of the boat's passenger cabin. Officers from the DLNR Division of Conservation and Resources Enforcement (DOCARE) along with the Hawai'i County Police Dept. are investigating the incident.
Now playing
00:47
Lava bomb hits Hawaii tour boat, injures 23
USGS
Now playing
00:50
Whirlwind of lava at Hawaii's Kilauea volcano
CNN
Now playing
02:05
Team uses drones to map lava in Hawaii
lava meets ocean
CNN
lava meets ocean
Now playing
02:09
Watch fast-moving lava flow into Pacific Ocean
hawaii community covered in shooting laval orig gr_00000000.jpg
hawaii community covered in shooting laval orig gr_00000000.jpg
Now playing
02:18
Shooting lava covers community
Isaac Krakauer/Facebook
Now playing
00:59
Lava 'river' engulfs home in minutes
Now playing
00:46
Blue flames burn during Kilauea eruption
Courtesy Tam Hunt
Now playing
00:58
Cracks open up beneath big island home
In this May 24, 2018 photo from the Federal Emergency Management Agency, lava erupts from a fissure in the Leilani Estates neighborhood near Pahoa on the island of Hawaii. Three lava flows from eruptions of Kilauea volcano are now flowing into the ocean off Hawaii's Big Island. Hawaii County officials say the third flow started pouring into the sea Thursday. Lava is spewing from a fissure in a rural community that's feeding the two other flows that are reaching the waves. (Grace Simoneau/FEMA via AP)
Grace Simoneau/FEMA via AP
In this May 24, 2018 photo from the Federal Emergency Management Agency, lava erupts from a fissure in the Leilani Estates neighborhood near Pahoa on the island of Hawaii. Three lava flows from eruptions of Kilauea volcano are now flowing into the ocean off Hawaii's Big Island. Hawaii County officials say the third flow started pouring into the sea Thursday. Lava is spewing from a fissure in a rural community that's feeding the two other flows that are reaching the waves. (Grace Simoneau/FEMA via AP)
Now playing
02:22
See damage from lava invading Hawaii
time lapse above hawaii volcano ORIG TC_00002109.jpg
time lapse above hawaii volcano ORIG TC_00002109.jpg
Now playing
00:49
Time-lapse from the skies above Hawaii's volcano
Now playing
01:42
Man hit by lava bomb describes gruesome injuries
title:  duration: 00:00:00 site:  author:  published:  intervention: no description:
MICK KALBER/TROPICAL VISIONS VIDEO/Paradise Helicopters
title: duration: 00:00:00 site: author: published: intervention: no description:
Now playing
01:21
Aerials show lava river in Hawaii
CNN
Now playing
02:07
See lava spew from Kilauea volcano
PAHOA, HI - MAY 5: In this handout photo provided by the U.S. Geological Survey, lava errupts from a new fissure from Luana Street after the eruption of Hawaii's Kilauea volcano on May 5, 2018 in the Leilani Estates subdivision near Pahoa, Hawaii. The governor of Hawaii has declared a local state of emergency near the Mount Kilauea volcano after it erupted following a 5.0-magnitude earthquake, forcing the evacuation of nearly 1,700 residents. (Photo by U.S. Geological Survey via Getty Images)
Handout/Getty Images North America/Getty Images
PAHOA, HI - MAY 5: In this handout photo provided by the U.S. Geological Survey, lava errupts from a new fissure from Luana Street after the eruption of Hawaii's Kilauea volcano on May 5, 2018 in the Leilani Estates subdivision near Pahoa, Hawaii. The governor of Hawaii has declared a local state of emergency near the Mount Kilauea volcano after it erupted following a 5.0-magnitude earthquake, forcing the evacuation of nearly 1,700 residents. (Photo by U.S. Geological Survey via Getty Images)
Now playing
01:12
Lava spills through Hawaii neighborhood
Lava shoots into the night sky from active fissures on the lower east rift of Kilauea volcano, Tuesday, May 15, 2018 near Pahoa, Hawaii. (AP Photo/Caleb Jones)
Caleb Jones/AP
Lava shoots into the night sky from active fissures on the lower east rift of Kilauea volcano, Tuesday, May 15, 2018 near Pahoa, Hawaii. (AP Photo/Caleb Jones)
Now playing
01:40
This is what it's like on the ground on Hawaii's Big Island
(CNN) —  

The US Coast Guard extended the required safety zone surrounding active lava flows in Hawaii after a flying hunk of lava hit a tour boat and injured 23 people.

The so-called lava bomb punctured the roof of a lava tour boat named Hot Shot on Monday morning in Kapoho Bay on Hawaii’s Big Island, the Hawaii County Fire Department said.

A flying hunk of lava tore a hole in the roof of a lava tour boat Monday in Hawaii's Kapoho Bay.
Hawaii DLNR
A flying hunk of lava tore a hole in the roof of a lava tour boat Monday in Hawaii's Kapoho Bay.

Boats in Hawaii were already required to be at least 300 meters, or nearly 1,000 feet, away from lava flows at all times, the Coast Guard said. However, certain commercial and research vessels were granted special permission to approach closer.

These boats were allowed to be up to 100 meters (330 feet) away, and last week, the Coast Guard lowered that safety zone to 50 (164 feet) meters, according to Matthew West, a Coast Guard spokesman.

But in the wake of the lava bomb injuries, the Coast Guard said all boats must adhere to the 300-meter rule.

Hot Shot was one of the boats with special permission to approach closer, West said. The lava tour boats have operated in the area for at least 20 years, the Coast Guard said.

Sara Muir, another Coast Guard spokesperson, said any time a boat gets near an active volcano, you are “accepting a higher level of risk.” Licensed mariners must rely on good judgment, she said.

Officials are interviewing the crew and passengers as part of the investigation, Muir said.

The Kilauea volcano erupted in early May, sending a smoldering flow of lava into residential areas on the Big Island. Kilauea was still erupting lava as of Sunday, according to the US Geological Survey.

’Everyone was screaming and crying’

In video taken from the tour boat when the lava bomb struck, a loud noise can be heard and then passengers begin to scream.

A witness who saw the boat return said rocks were all over it, and some people had burns and gashes on their legs as they left the boat. One person was taken off on a stretcher.

Twelve patients were treated and released from Hilo Medical Center by 1 p.m. on Monday, according to spokeswoman Elena Cabatu. One woman who was in serious condition with a broken leg was flown to Oahu for further treatment, she said.

Lindsay Rostron, a passenger on the tour boat, posted video of the incident and said it was the “scariest moment” of her life.

At 15 seconds into the video, a large black plume and brightly glowing lava shoot out of the water toward the boat, causing a loud noise and prompting fearful screams from the passengers.

(Warning: Turn down the volume in your headphones before watching.)

Erin Walsh, who was on the boat with her boyfriend, told CNN affiliate KHON that they were oohing and aahing at the scene until the lava bomb surprised everybody.

“I didn’t even believe that this was coming toward us. We’d been watching it. It was so beautiful,” Walsh said. “Then it’s like, oh my God.”

The passengers began screaming and trying to find cover, Will Bryan, Walsh’s boyfriend, told KHON.

“There’s nowhere to go. You’re on a boat that’s so big. You’re just getting pelted. There’s no safe spot on the boat. You’re just getting hammered wherever you’re at,” Bryan said.

Walsh added, “Everyone’s trying to escape, so I just went to the middle of the walkway aisle, dropped to the ground, and was just covered in lava. It was crazy.”

A witness on another lava boat said the explosion sent black sand everywhere and the rocks on the boat’s roof were red hot.

“I saw the glow on top of the boat,” said the witness, who spoke to CNN on condition of anonymity.

About 50 rocks were on the boat, including three about the size of basketballs, the observer said. The witness’ boat approached the Hot Shot to help, and “everyone was screaming and crying.”

A first responder to the scene relayed what happened to one woman in a call with emergency dispatch.

“A piece of lava flew toward the boat; she closed her eyes, and the next thing she knew she felt pain to her left leg and to her lower back.”

The lava bomb left a large hole in the boat’s roof, the fire department said. A railing was also damaged.

CNN’s Jay Croft, Maya Eliahou, Scott McLean and Chuck Johnston contributed to this report.