Three teenagers have been charged over a fire that destroyed a wing of the disused Wainuiomata College.
A fire ripped through the school on Saturday night.
This morning Lower Hutt police said they had arrested a 14-year-old female and two 15-year-old males in connection with the blaze.
The trio appeared in Lower Hutt Youth Court this morning over the fire.
All three, charged with arson, were remanded on bail by Judge Anthony Walsh till Wednesday.
The three-storey block contained 14 classrooms.
The attack was the latest on an abandoned school.
Wainuiomata College was one of five schools in the area shut down in 2001 because of falling rolls. Six years later the site was given to the Port Nicholson Block Settlement Trust as part of a Treaty settlement.
Neighbours, police and firefighters say the school has been a frequent target of broken windows, graffiti, and rubbish bin fires.
On Saturday night, flames destroyed the three-storey block at the back of the school and 10 fire trucks were needed to put out the blaze.
Most had been stood down yesterday morning but smouldering hot spots were still being sprayed down by an aerial hose.
Former firefighter Bruce Walker, whose house backs on to the school, said he and his wife were woken by the sound of the fire about 12.30am.
"We heard a banging, and we listened for about five minutes, and by the time we got up it was well involved."
Mr Walker said he had called the police numerous times over the past 10 years about people causing trouble at the school.
When the school closed they had a row of poplar trees between their house and the school chopped down so they could keep a better eye on the place.
Acting Detective Sergeant Anthony Tebbutt, who was at the scene yesterday morning, said the fire was being treated as suspicious.
The school was a ripe target for vandalism. "You only have to look at all the broken windows and the graffiti to see that."
Chief fire officer David Smith said by the time firefighters arrived the flames had ripped through the building "end to end".
"We had to do what we call surround and drown - we couldn't send any men in there because it was just too dangerous."
Diggers arrived yesterday afternoon to raze the building, Mr Smith said.
A Port Nicholson Block Settlement Trust spokesman said the damaged building was insured. A security guard would be hired to protect the site.
The building was not in a "usable" state before the blaze and the trust had been still making a decision on how to use it. "We're working with the authorities to get the building cleaned up as quickly as possible."
Insurance assessors were expected to visit the site today, the spokesman said.
Schools closed down by the government have been rife with arson attacks.
In February, Masterton officials threatened to force the Office of Treaty Settlements to demolish abandoned school buildings at Lansdowne School that were gutted in a fire last November.
It was one of more than 40 fires in the Wairarapa since the government-ordered closure of six of the district's schools in 2004.
Labour MP Trevor Mallard, who was in charge of amalgamating Wainuiomata's schools in 2001, said building reports done at the time showed the block and another next to it were in need of extensive maintenance and were suffering from "concrete cancer".
Since it closed the school has been used intermittently by after-school groups, Civil Defence training, and sports groups. The first season of the comedy show Seven Periods With Mr Gormsby was filmed there in 2005.
- The Dominion Post