'Sonic Boom': Explosion Rocks Christchurch

Six people have been rushed to hospital after a massive explosion destroyed a house in New Zealand and significantly damaged five others.

The explosion rocked the neighbourhood of Northwood, Christchurch at about 10.30am on Friday.

The impact was so loud, one nearby resident described it as a "sonic boom" that "shook" buildings.

Half a dozen people, all believed to be in their 50s and 60s, were taken to hospital with injuries ranging from serious to critical, while 50 other residents were evacuated from nearby homes.

One of the first people on the scene, retired police officer Bradley Culver, said he thought a plane had crashed behind his house and that it was lucky no one was killed.

"I’ve seen a lot in my day and that was a pretty severe explosion. I’ve never seen anything like that," he told Star Kiwi.

“We started pulling people out of the rubble and asked how many people were [left] in the house and they said five and we were able to get all five of them out before the emergency services arrived.”

Photo: James Looyer via Facebook

A gas leak is being blamed but it's not yet clear what caused the leak.

"We've got our gas experts having a look at that," St John territory manager Craig Dowling told the New Zealand Herald.

"Once we've got the scene safe ... we'll look at what's caused this and carry out an investigation with police and WorkSafe."

Photo: James Looyer via Facebook

Witness Tom White told local media that concrete tiles from the roof of the house had been blown 100m in every direction.

"The house is matchsticks. It's totally blown apart. It's caused a lot of destruction to other houses, its blown the garage door right off the next-door neighbour's house," he said.

New Zealand police confirmed there five other properties severely damaged and another 17 impacted by flying debris.

Fire and Emergency New Zealand said the explosion came from the area's reticulated gas supply and caused multiple injuries.

Footage taken by James Looyer, a witness at the scene, shows an enormous pile of debris where the home once stood.

Wooden beams, insulation and twisted metal littered the scene as flames shot up into the air.

'Sonic Boom': Explosion Rocks Christchurch

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