The Fire Service says workers at a scrap metal factory in South Auckland are incredibly lucky to have escaped unharmed after a massive explosion on Wednesday night.
Fire crews extinguished a large fire caused by the blast just before 7pm at the National Steel plant, which recycles car bodies and other scrap metal for export in the suburb of Wiri.
The Fire Service said the blast was felt in suburbs several kilometres away and shook houses and buildings, including the Wiri home of Anne Hurley, a nun at the Sisters of Mercy. Sister Anne said the air was filled with an acrid smoke and the blast gave them quite a fright.
Acting Auckland area commander Roger Callister said the Fire Service believed the explosion happened when a gas canister was crushed by machinery. Conveyor belts and other equipment then caught on fire and several walls were blown out.
Mr Callister said about six people working at the factory were very lucky to escape a blast that size. "Extremely lucky, given the force of the explosion, that they weren't in an area that they've been seriously injured or even worse."
The factory's owner, Roshan Nauhria, said workers checked cars and other scrap metal very carefully but the occasional gas cylinder or petrol tank was missed.
Mr Nauhria said smaller explosions happen once every two or three months but none of his workers have ever been injured
The Ministry of Business, Innovation and Employment, which looks after workplace safety, said an inspector was making preliminary inquiries.
The ministry said it would look into the explosion and health and safety processes in the workplace, before deciding whether a further investigation would take place.
Police were also investigating the incident.