CNN  — 

Residents on Hawaii’s Big Island faced the threats of more earthquakes, lava and dangerous gas after the Kilauea volcano erupted, spewing high levels of sulfur dioxide and molten rocks into neighborhoods.

A magnitude 6.9 quake struck the area Friday, jolting homes already threatened by volcanic eruption. The earthquake, one of dozens to hit the area in 24 hours, was the most powerful on the island since 1975, the US Geological Survey said.

The volcano, which erupted Thursday, already had driven hundreds of people from their homes.

Steam rises Friday from cracks in a road near Leilani Estates on Hawaii's Big Island.

The jolts and tremors have been consistent, said Ikaika Marzo, who lives on the Big Island.

“There are still plumes going out. There’s a couple cracks that’s close by that still have steam coming out,” Marzo told CNN affiliate KHON on Friday. “There’s a lot of glow, a lot of fires.”

The volcanic activity will continue, Civil Defense Administrator Talmadge Magno said Friday. “It doesn’t look like it is slowing down.”

At least seven volcanic vents have opened in Leilani Estates, according to the Hawaii Civil Defense Agency. All residents of Leilani Estates, a community of about 1,700 people near the Big Island’s eastern edge, and nearby Lanipuna Gardens have been ordered to evacuate.

‘Just basically heartbreak’

Timothy Trun was among a dozen who evacuated from his farm Thursday as he and others were about to sit down to a goodbye dinner for a friend.

“It’s been a real shocker,” he told CNN on Saturday. “We’re about to enjoy eating dinner, and the cops show up and tell us you have to go, and everything changes in an instant. You have five minutes to pack your bags with what you think you’re going to need and you’re off.”

Neil Valentine and his family also left their home Thursday night in Leilani Estates. In short order, he saw a video on social media showing lava splashing and bubbling a few feet from his home, he told CNN affiliate KITV.

“Just basically heartbreak,” he said of the scene. “My wife and I have been married going on 26 years. It was pretty much our dream home that we’ve been looking for all this time. Just knowing that we’re not going to have a house, my wife is still in tears.”

Harry Kim, mayor of Hawaii County, said the government will support residents who want to go back to their homes to pick up some belongings.

Cracks in Kilauea volcano’s rift zone – an area of fissures miles away from the summit – erupted Thursday and early Friday, spurting lava near the island’s eastern edge.

‘We had to evacuate’

Stephen Clapper was one of the evacuees. He asked his mother Friday to pack a bag, just in case.

“We had to evacuate. My mother was out of portable oxygen, so that’s a first concern. She’s 88 years old,” he told KHON.

Lava set trees ablaze and threatened homes as gas spewed out of cracks in the ground. Clapper went back to the house, got his mother and the dogs, swept up some of his clothes in one arm and took off for a shelter.

Under the watch of authorities, Leilani Estates residents line up Friday amid evacuation orders.

Hundreds without power

About 14,000 customers of Hawaii Electric Light lost power immediately after Friday’s 6.9 magnitude quake. Power has been restored to about half those customers, but sulfur gas levels in some areas are too high for employees to work, utility spokeswoman Rhea Lee-Moku said Friday evening.

“When you are exposed to that level of SO2 in the Leilani Estates area, you need more protection than we have available to us,” she said.

An ash plume rises Thursday above the Kilauea volcano on Hawaii's Big Island.

Exposure to high levels of sulfur dioxide can be life-threatening, according to the federal Agency for Toxic Substances and Disease Registry. Volcanic eruptions can release the gaseous compound, and Hawaiian fire department personnel have detected high levels of it in the evacuation area, the civil defense agency said.

Breathing large amounts of sulfur dioxide can result in burning of the nose and throat, and breathing difficulties. Senior citizens, the young and people with respiratory issues are especially vulnerable to the gas, the state’s Emergency Management Agency said.

Gov. David Ige said he’s activated the Hawaii National Guard to help with evacuations and security.

Kilauea is one of the world’s most active volcanoes. It’s in Hawaii Volcanoes National Park, which closed Friday and evacuated all visitors and nonemergency staff.

CNN’s Jason Hanna, Chris Boyette, Dakin Andone, Keith Allen and Gianluca Mezzofiore contributed to this report.