The investigation is continuing into the cause of Tuesday's fatal helicopter crash that killed a Christchurch couple and seriously injured three children. Andrew Davidson and his wife Lin Chen died in the crash whilst their two children along with a schoolfriend were seriously injured and are in Wellington Hospital. The family had planned to stop for lunch at The Store, a popular cafe and campground at Kekerengu, around half an hour north from Kaikoura but as the helicopter came to land, witnesses say the aircraft spun out of control and plummeted to the ground. Mr Davidson was the founder and general manager of electronics company Enatel Motive Power. The company's managing director Richard Jenman told our reporter Rachel Graham that Mr Davidson was a stalwart of the tech industry. And it's the quick actions of witnesses and nearby residents that are credited with saving the lives of the three children. Bystanders raced to pull the wreckage of the aircraft from the Kekerengu River mouth and get the children out before emergency services arrived. Nathan Rarere spoke with Kaikoura Mayor Craig Mackle.