Civil Defence in Southland is urging business owners to ensure their buildings are safe before opening for work on Monday, after a heavy snowfall caused the stadium roof to cave in and damaged other buildings.
Stadium Southland was largely destroyed when the roof caved in on Saturday and most of the building will have to be torn down and rebuilt. The velodrome is the only part of the venue unscathed.
Snow caused the roof of Wrens Paint Supplies in Yarrow Street to collapse early on Sunday and the roof of the New World Supermarket on Windsor Street has also partially collapsed.
Drifts of up to 15 centimetres have been recorded in Invercargill and the region's Civil Defence group controller, Neil Cruickshank, says if businesses still have a considerable amount of snow on their roofs they should seriously consider not opening or wait until later in the day.
He says the main concern is about flat roofed buildings with internal spouting systems.
Mr Cruickshank says another cold front is due to hit the lower South Island on Monday and more snow could further weaken structures already bearing the weight of the previous snow fall.
He says building owners concerned about roof structures should contact an engineer.
School closures in Southland will be left to individual boards of trustees and decisions will be made on Monday morning.
Invercargill City Council will meet on Monday to discuss the collapse of the roof on Invercargill's$10-million stadium.
Mayor Tim Shadbolt was unable to return from Christchurch to Invercargill on Saturday as the airport was closed, and a backlog of passengers on Sunday meant getting a seat on a flight was difficult.
But he says it's clear the council needs to meet on Monday to discuss the ramifications of the stadium roof collapse.
Southland roads are extemely icy and police say anyone who does not need to travel should stay off the roads.
Stadium soundly built, says former trust chairman
One of the key figures in the building of the stadium in Invercargill says there was no fault in its construction.
Ray Harper, former chairman of the Invercargill licensing trust, which spearheaded the building of the stadium, says the incident is an act of God.
"This is freak a circumstance," he says. "Never in my life, in 80 years, have I seen Invercargill with so much snow."
Mr Harper, who's also had 33 years experience as a master builder, says the project used the best engineers and architects, and everybody in Southland was proud of the building.
He says it's a shock, but the venue is insured and will be rebuilt as good as new.
Tennis matches just finished
Some junior tennis matches had just finished when the roof caved in, and a group of players had left.
Tennis coach Andre Van Rooyen, who'd just been been taking a lesson at the stadium, says the roof collapsed in a matter of seconds, with loud thundering noises.
He says he was among four or five people still in the building and ducked for cover behind a wall.
The complex houses seven playing courts and seating for 2,000 people.
Weather forecaster Andy Fraser says the snow was very heavy, with a high water content.
Mr Fraser, a forecaster at 45 South Weather Service based in Invercargill, says the city is prone to watery snow because it's close to the coast, unlike inland areas which get lighter snow.
He says Invercargill gets a snowfall of this weekend's magnitude every 10 to 15 years, but he would not class it as a freak event.
The MetService says Southland says more snow is predicted for Monday onwards.