Police are urging drivers to take care after icy roads in the South claimed another casualty yesterday.
Thirty passengers travelling on a tourist bus which crashed on the Te Anau-Mossburn Highway just before 9am are lucky to be alive, according to Mossburn locals, who say the recent frosts have been particularly heavy.
Police said the bus slid on black ice near Mossburn and the New Zealand Transport Authority attributed a "light shower of rain" about 8am to the rapid deterioration of roads in the area.
A 9-year-old boy remained in Dunedin Hospital under observation last night.
He was one of 22 people transported to Southland and Dunedin Hospitals after the Worldway bus crashed.
St John communications co-ordinator Alena Lynch said three passengers - the boy, a 55-year-old man with chest and back pain, and a 52-year-old woman with chest, shoulder and neck pain - were flown out by helicopter.
Because many of the passengers did not speak English, the patients were accompanied by escorts from the bus, including an interpreter, who had a fractured ankle, she said.
A group of passengers with moderate injuries were taken by ambulances to Southland Hospital and shortly after another group with minor injuries was also transported to the hospital.
The bus driver was taken to Southland Hospital as a precaution.
Southland area manager Peter Robinson said the roads were inspected at 6am and 7am and no obvious ice issues were evident on the section where the crash happened.
At least three other crashes occurred in the area and yesterday police warned the public to drive on the affected roads only if "absolutely necessary".
Southland district councillor John Douglas, of Mossburn, said he had heard of some lucky escapes involving motorists and ice.
The accident was not unexpected in the "semi-mountainous terrain" during a "particularly cold snap", he said.
"Let's hope this run of frosts may be coming to an end."
In South Otago earlier this week, heavy frosts and ice caused havoc. There have been more than 15 crashes in the area since Monday, although most drivers escaped major injuries.
In Central Otago, icy roads in the Lindis Pass saw four people injured when their car ended up upside down in a creek about 1.30pm on Tuesday.
In yesterday's incident, the bus was travelling at a speed of 40kmh-50kmh behind another bus, when it slid and spun 180 degrees, before coming off the road backwards, rolling on to its side and hitting a power pole.
Power in the area was cut because of the impact.
Southern Lakes Helicopter pilot Mark Deaker, who attended the crash, said the roads were like an ice-skating rink.
He flew a doctor to the scene and later transported two passengers to Southland Hospital.
"It just happened to be at that particular change in the weather where dry and frosty roads become wet and icy," he said.
"What happened to them could have happened to anyone."
Conditions were "what you would expect in the mountains" and the uninjured people were quickly taken to the Mossburn Fire Station to escape the freezing temperatures.
"They were pretty well cared for," Mr Deaker said.
The uninjured passengers were later transported to Te Anau.
Investigations into the crash are continuing.
Mr Robinson said a heavy-vehicle crash investigator was at the scene yesterday assisting police.
