An explosion at a Hawke's Bay school was caused by a parent using a portable gas cooker incorrectly to cook homemade meat patties.

A Whangarei lunch bar and an office have been badly smoke-damaged after a deliberately-lit fire.

Education officials have contacted Mayfair School after a gas canister exploded and injured a parent on the school grounds.

A huge fire that raged for almost 24 hours south east of Invercargill has destroyed more than 400ha of an internationally recognised scientific reserve.

A gas cooker has exploded at a Hawkes Bay school, injuring one person, emergency services say.

Helicopters will join efforts to control a large bushfire this morning that has already burned more than 400ha of conservation land near Invercargill.

Seventy-four-year-old Eltham Fire Brigade volunteer Max Mackay has been awarded the United Fire Brigade association 50-year service medal.

A Fire Service has disagreed strongly with some earlier witnesses at the CTV inquest that there was confusion over leadership on February 22 last year.

Search and rescue units were told to stop scouring the collapsed CTV Building's rubble for survivors within 24 hours of it coming down.

A merino singlet may have saved the life of a grandfather who suffered horrific burns when the car he was working on exploded.

A coroner's inquest today heard from a senior search and rescue expert who described the "chaos" at the disaster site when he arrived two hours after the building's collapse.

The inquest into the CTV deaths has heard of frustrations caused by delays and chaos in the hours after the catastrophe.