The chunk landed on the boat's roofImage: Reuters/Department of Land and Natural Resources
First responders rushed the injured to Hilo Medical Center after the boat returned to Wailoa Boat Harbor.
Hawaii County Fire Department said a woman in her 20s was in a critical condition with a broken thigh
bone. Twenty-two others suffered from burns and scrapes, including 12 who have since been released from the hospital.
The passengers were part of a regular service tour that allows people to watch lava flow into the ocean. The US Coast Guard allows tour operators to move their boats up to 164 feet (50 meters) from the flow.
Passengers told DLNR that the boat was outside the danger zone when the lava chunk struck the roof.
Hawaii's Kilauea volcano eruption causes weeks of destruction
Kilauea's lava flows have threatened thousands of people's homes in rural Hawaii. Over 40 buildings have been destroyed so far by the eruptions, with experts unsure of when the volcano will calm down.
Image: Reuters/T. Sylvester
Lava meets the sea
Lava from the Kilauea volcano pours into the ocean from Hawaii's main island, while volcanologist Jessica Johnson monitors the developments.
Image: Privat
Lava meets geothermal plant
A lava flow from the Kilauea volcano approaches the Puna geothermal power plant on Hawaii's Big Island. The plant, which provides 25 percent of the island's electricity, has been shut down due to the encroaching lava. It is believed to be the first time a lava flow has forced the closing of a geothermal plant.
Image: Getty Images/M. Tama
One of the world's most active volcanos
Kilauea, which is one of the most active volcanos in the world, has been erupting, oozing lava, and spewing toxic gases for weeks on Hawaii's Big Island. Experts aren't certain when Kilauea will calm down again.
Image: Reuters/T. Sylvester
Kilauea starts smoking on May 3
Around 2,000 people were evacuated from the area around the Kilauea volcano after it erupted and a lava fissure opened on May 3. In the weeks that followed, new eruptions and lava streams threatened the homes of residents located miles away.
Large streams of lava rising up from huge cracks in the earth threatened neighborhoods located near the volcano. The molten rock spilled over on to streets and has destroyed over 40 homes and other buildings.
Image: Reuters/Handout/USGS
Poisonous gasses and glass particle steam
Thousands of residents voluntarily left their homes due to high levels of toxic sulfur dioxide gas that spewed out of vents in the volcanic fissures. Officials also warned residents not to go near the lava that has poured into the ocean — the phenomenon causes the formation of clouds of hydrochloric acid and steam carrying fine glass particles.
Image: Reuters/T. Sylvester
Massive damage to roads
The eruptions and volcanic fissures created massive damage to roads and highways. Two lava streams crossed over a main coastal highway that is used as an escape route for residents.
Image: Reuters/USGS
Playing golf with an ash cloud
Other locals and tourists took a more relaxed approach to the volcanic eruptions. A group of people finished playing a round of golf while others take pictures of a massive ash cloud spewing from Kilauea.
