Six people were injured and dozens of homes evacuated in the New Zealand city of Christchurch on Friday after a huge gas explosion destroyed one home and damaged others.

The explosion was felt far from the neighborhood, with some fearing it might have been an earthquake or a bomb. Footage of the aftermath shows the home was reduced to a pile of wood and rubble with flames coming out.

Several people who were inside the home at the time survived, including one who remained in Christchurch Hospital in a critical condition. Health authorities said four other patients remained in stable conditions while a sixth person had been discharged.

In this imaged made from a video, a firefighter works inside a damaged home following a gas explosion in Christchurch, New Zealand Friday, July 19, 2019. Several people were injured and dozens of homes evacuated in the New Zealand city of Christchurch on Friday after a huge gas explosion destroyed one home and damaged others. (TVNZ via AP)

In this imaged made from a video, a firefighter works inside a damaged home following a gas explosion in Christchurch, New Zealand Friday, July 19, 2019. Several people were injured and dozens of homes evacuated in the New Zealand city of Christchurch on Friday after a huge gas explosion destroyed one home and damaged others. (TVNZ via AP)

Authorities confirmed it was a gas explosion although said they're still investigating the cause. Relatives said the occupants had been having problems with their gas fire.

Neighbor Brad Culver, a U.S. citizen who has been living in New Zealand for eight years, told Television New Zealand he thought at first a plane had crashed and ran outside.

"The house was in a complete pile of timber and rubbish, you couldn't even conceive that it was a house," he said. "There was nothing left standing."

This image taken from a video shows a damaged home following a gas explosion in Christchurch, New Zealand Friday, July 19, 2019. Several people were injured and dozens of homes evacuated in the New Zealand city of Christchurch on Friday after a huge gas explosion destroyed one home and damaged others. (NEWSHUB via AP)

This image taken from a video shows a damaged home following a gas explosion in Christchurch, New Zealand Friday, July 19, 2019. Several people were injured and dozens of homes evacuated in the New Zealand city of Christchurch on Friday after a huge gas explosion destroyed one home and damaged others. (NEWSHUB via AP)

Culver said he started pulling people out.

"They all appeared to be O.K., they were in shock but had superficial cuts, bruises, that sort of thing. It didn't look like any life-threatening injuries," he said. "Miracle, really a miracle."

Another neighbor, Ann Gray, told the network she was standing at her kitchen bench just after 10 a.m. when she felt what she thought was a massive earthquake.

This image taken from a video shows a damaged home following a gas explosion in Christchurch, New Zealand Friday, July 19, 2019. Several people were injured and dozens of homes evacuated in the New Zealand city of Christchurch on Friday after a huge gas explosion destroyed one home and damaged others. (NEWSHUB via AP)

This image taken from a video shows a damaged home following a gas explosion in Christchurch, New Zealand Friday, July 19, 2019. Several people were injured and dozens of homes evacuated in the New Zealand city of Christchurch on Friday after a huge gas explosion destroyed one home and damaged others. (NEWSHUB via AP)

"I looked up and I could see all the stuff going up in the air so I came outside, it was all up in the air like it was huge and it was so high, bits of wood," she said, adding that "it took a while to come down, I thought it was going to come down on top of my house."

Belinda Blanchfield told the news website Stuff that her parents along with other relatives and friends were inside the home at the time of the explosion.

"It's our worst nightmare," she said. "My parents are the absolute kindest people ever."

Blanchfield's husband Paddy Blanchfield told Stuff the occupants had been having issues with their gas fire in recent days and had been awaiting repairs, although it was unclear if those had taken place.

Fire and Emergency New Zealand said in a statement that as well as the destroyed home, five neighboring properties were affected by fire and another 17 were impacted by debris. It said it extinguished the rubble fire and was investigating the scene.