"All of a sudden, there was a hell of bang, and then stuff just flew everywhere," Nicole Laidler said last night.
The Dunedin woman was driving to Queenstown in her Subaru Impreza with three passengers at 12.30am yesterday when it struck a row of stones laid across one and a-half lanes of Kawarau Gorge Rd, near McNulty Rd, about 2km from Cromwell.
She reckoned she was travelling just under 100kmh.
Three tyres and mag wheel rims on the car were destroyed, its windscreen was cracked and floorpans dented.
"It was like a tsunami hit the back seat floor. It's all rippled."
The impact when the car hit the rocks was so big, Miss Laidler thought the engine had dropped out.
She kept control of the car and pulled over.
While she and her friends were trying to find out what had happened, a second vehicle hit the rocks and damaged a tyre.
That vehicle could be driven away once the tyre was changed.
Miss Laidler and her passengers moved the rocks off the road.
Senior Constable John Chambers, of Cromwell, said he could not imagine the rocks had been placed on the road by an individual.
"I think it would have been young hoons on their way to or from the Blossom Festival [in Alexandra].
"They probably thought it was a prank or a joke but they don't realise they have put other people's lives at risk."
He assumed the rocks had been placed on the road not long before Miss Laidler struck them and wanted to hear from anyone who had seen people acting suspiciously in the area.
If found, the offenders would face charges of endangering lives by an act of criminal nuisance, Snr Const Chambers said.
A nearby resident who stopped to help Miss Laidler offered the group a bed for the night, which they accepted.
A friend took three new tyres and wheels to Cromwell and the car was able to be driven back to Dunedin yesterday, she said.
Miss Laidler was amazed last night at the stupidity of someone doing something like that.
"What if a family had been driving there?
"What if you were towing a caravan?
"Someone's idiotic behaviour could have killed four people last night."
