The Fire Service is investigating a suspicious blaze that has severely damaged a building in a Christchurch suburban mall.
Fire crews were called at 1.46am on Saturday to the single-storey Charity Barn building in New Brighton Mall.
The Fire Service said fire engines arrived within two minutes but the structure was already well ablaze. Six units and about 30 staff attended the fire.
Assistant area commander Dave Burford said crews managed to save buildings on either side of the burning shop by putting up screens of water.
Investigators are working on finding the cause of the blaze, but Mr Burford said hanging girders and beams are making the building too dangerous for officers to enter.
He said the centre of the building has collapsed and the Fire Service is negotiating with Christchurch City Council and insurers to demolish the building.
The 1000sq m building stocked items such as second-hand clothing and recycled paint.
Other retailers in New Brighton Mall remain open.