LEAD STORY: Residents flee blaze | Hawkes Bay News | Local News in Hawkes Bay

Residents of about a dozen homes in Waipukurau got an early morning "you have to leave" call from police as an 80-strong team of firefighters took a cautious approach to attacking a huge blaze at the old Waipukurau Hospital today.

The reason for the evacuation and cautionary "external attack only" approach were thick, billowing clouds of smoke which fire crews and police feared may have contained burned asbestos.

"A lot of these older buildings had asbestos in them," Hawke's Bay Fire Service scene commander Allan Bamber said.

At first light, winds in the area meant the billowing smoke from the fire, which was reported about 1.30am, was going straight up, he said, but then it began to "clag" and drop - moving toward houses just north of the old Porangahau Rd hospital which closed in the late 1990s.

For some residents spoken to today, the fire came as no surprise, as the vacant building had long been a target for vandals and taggers.

One resident described it as "an eyesore".

The size of the fire, and potential for contamination, saw fire crews called in from Napier and Hastings, as well as all surrounding volunteer stations in the area,

At the height of the blaze, 17 appliances and more than 80 firefighters were at the scene.

"Because of the possibility of asbestos and the danger of walls collapsing, it was an all external attack," Mr Bamber said.

Some parts of the three-storey building had collapsed at the blaze's peak.

The fire spread quickly through the large multi-winged building and he estimated more than a third of it had beendestroyed.

Crews were still cleaning up the last of the main fire spots at 9am and Mr Bamber said putting the fire out completely would be "an all-day job".

Volunteer crews had been stood down and six units remained at the scene to dampen down hotspots and decontaminate the area.

Central Hawke's Bay emergency-management officer Bruce Kitto said police and fire officers began evacuating about 40 people from their homes about 3am. They were taken to Memorial Hall in the township, although Mr Kitto said several went to stay with friends or relatives away from the affected area.

Those who remained at the hall were allowed to return to their houses at 8.30am.

Civil Defence and Salvation Army had looked after the evacuees.

Mr Bamber said fire-safety officers and police had begun an investigation into the possible cause of the fire.

There were no immediate indications on how it started.