Hawaii volcano's next eruption could spew lethal gas and boulders big as fridges

Residents near one of the world’s most active volcanos were warned Thursday of rising levels of toxic gas, as concerns on the ground grew that Kilauea could blow at any minute.

A wind change could bring even more sulfur dioxide gas to the southeast section of the Big Island.

“Due to decreasing tradewinds, residents are advised to monitor their sensitivity to increased levels of (sulfur dioxide),” a text alert message sent Thursday said.

If inhaled in large quantities, the wafting gas can be fatal.

The new warning comes as Hawaii Gov. David Ige says mass evacuations may occur as more cracks, or fissures, are detected.

Kilauea has destroyed 36 structures — including 26 homes — since May 3, when it began releasing lava from vents about 25 miles east of the summit crater. Fifteen of the vents are now spread through the Leilani Estates and Lanipuna Gardens neighborhoods.

About 2,000 people have been evacuated from the neighborhoods, where scorching lava has oozed from the ground.

The volcano, which has been spitting and sputtering lava for a week, has also imperiled a geothermal energy plant, the  Puna Geothermal Venture plant. Ige said crews at the plant near the lava outbreak accelerated the removal of stored flammable fuel with safety in mind.

Barbara Lozano, who lives within a mile of the plant, said she would have thought twice about buying her property if she had known the risks.

"Why did they let us buy residential property, knowing it was a dangerous situation? Why did they let people build all around it?”

- Resident Barbara Lozano, who lives near a geothermal energy plant imperiled by volcanic activity.

“Why did they let us buy residential property, knowing it was a dangerous situation? Why did they let people build all around it?” she asked worriedly.

Coffee farmer Palikapu Dedman, 71, has dedicated half his life to battling the plant that sits on the long slopes of Kilauea. He and other native Hawaiians say the plant desecrates traditional beliefs and angers Pele, the goddess of fire, who lives at the summit crater.

Now that the plant is threatened by Kilauea, Dedman says he feels vindicated.

"You really can’t hurt Pele,” he said. “It’s just reinforcement of my beliefs — she’s present! And the plant could get covered by lava tomorrow.”

The Hawaiian Volcano Observatory (HVO) warned that the growing instability in the area could mean other areas of the island also could be at risk.

Ige told CNN that it’s been tough for residents.

“There’s a sense that it’s Mother Nature,” he said. “The lava flow is unpredictable. It’s hard to determine which direction it will go. It starts and stops on a whim. That’s the uncertainty that residents are faced with.”

Geologists warned Wednesday that Kilauea could soon experience explosive eruptions from its summit, and launch “ballistic” rocks and ash into the air.

The next explosion could hurl ash and boulders the size of refrigerators miles into the air, shutting down airline traffic and endangering lives in all directions.

“If it goes up, it will come down,” said Charles Mandeville, volcano hazards coordinator for the U.S. Geological Survey. “You don’t want to be underneath anything that weighs 10 tons when it’s coming out at 120 mph.”

The added threat of an explosive eruption could ground planes at one of the Big Island’s two major airports and pose other dangers. The national park around the volcano announced that it would close because of the risks.

“We know the volcano is capable of doing this,” said Mandeville, citing similar explosions at Kilauea in 1925, 1790 and four other times in the last few thousand years. “We know it is a distinct possibility.”

The threat of explosive activity will rise as lava drains from the summit of Kilauea and explosions will be possible in the coming weeks if the lava dips below the groundwater table, the U.S. Geological Survey (USGS) said.

If lava drops below the groundwater level, it can heat up the water and create steam.

The steam would then build in pressure as rocks fall and form a dam within the volcano’s walls, and ”cause steam-driven explosions” with “very little warning,” according to the HVO.

The volcano then could eject “ballistic rocks” of lava up to several feet in diameter, the USGS said. It also may send pebbles shooting into the air several miles away.

A similar 1924 explosion threw pulverized rock, ash and steam as high as 5.4 miles into the sky, for a couple of weeks. If another blast happens, the danger zone could extend about three miles around the summit, land all inside the national park, Mandeville said.

Fox News’ Frank Miles and Stephen Sorace, and The Associated Press, contributed to this report.