A doorbell camera has captured the roar as a house exploded in Christchurch on Friday morning.
Car alarms can be heard ringing after debris fell following the incident.
The home on Marble Court in Northwood, which had been serviced by a gas contractor the previous day, was reduced to a pile of timber after it exploded at around 10.15am.
Several people were injured, including one person who still remains in a critical condition at Christchurch Hospital. Another person is being treated at the serious burns unit at Auckland's Middlemore Hopsital.
The house was destroyed, while five others are "severely affected" and 17 were impacted by debris, Fire and Emergency New Zealand said.
The cordon was reduced yesterday afternoon to include Marble Court houses only, and the outer cordons have been lifted.
The scene examination continued today.
Witness at the scene Ann Gray told 1 NEWS her house shook and she originally thought the explosion was an earthquake, she would have guessed about 7.5 magnitude.
But then saw debris, including wood, billow into the air.
"It was massive ... bits of wood and everything," she said. "It was like the whole house had exploded."