A construction worker seeking cover in a portacom during an Auckland tornado died when the wind funnel hurled the structure through the air, a coroner has found.
Coroner Katherine Greig has released her findings into the 2011 death of Benedict Dacayan.
He was working as a quantity surveyor for Fletcher Construction at an Albany building site when a tornado tore through on May 3.
Wind speeds were estimated to have reached 150km/h to 200km/h.
The coroner said a two-tonne portacom Mr Dacayan was likely inside was "picked up and hurled by the tornado, disintegrating in mid-air".
He was found 45m away in a car park, suffering serious head and chest injuries. Despite attempts to revive the father of two, he died in an ambulance on the way hospital.
A Department of Labour investigation found no fault with Fletcher Construction, but recommended carrying out risk assessments on portacoms and securing and anchoring them to the ground.
Engineer Geoff Chilcott was hired by Fletcher Construction and he said tying the portacom down would've made little difference in holding the building to its base in the tornado.
The coroner accepted Fletcher Construction did not breach any safety standards over the portacom and nothing could have been done differently to prevent Mr Dacayan's death.
Coroner Greig recommended WorkSafe and the Ministry of Business, Innovation and Employment consider the safety of temporary accommodation and if such structures need to be secured to the ground.