Their trampoline, which had been tethered to the ground in their back yard, had been ripped from its moorings and carried on to the nearby golf course.
Witnesses from the petrol station across the road rushed over to check the family was unharmed and to relay what they had seen. Among them was Dunedin broker Peter Young, who was in Central Otago on a golf trip at the time.
"I noticed near the Big Fruit, there was a big dust storm twirling round," Mr Young said.
When he glanced back a few moments later he saw "a trampoline flying through the air".
The trampoline was carried for about 30m, two or three metres off the ground, before turning at a 90 degree angle, hitting the ground, and rolling at high-speed for another 200m or so into trees on the golf course. He then saw the caravan lift about 10ft into the air before overturning and dropping to the ground again.
"I couldn't believe what I'd seen. It was quite bizarre."
The caravan was extensively damaged by the tornado, while the trampoline was the third the Christiansens had lost to high winds.
"I don't think we'll have a fourth. I think lesson learnt," Mr Christiansen said.
Other Cromwell residents also reported items being lifted off the ground by powerful, circular winds on Friday evening.
In January 2009, mini tornadoes tore off a section of the Bannockburn Hotel's roof, and in July of that same year, a whirlwind whipped through an area north of Cromwell, ripping apart an implement shed and lifting an entire roof off a barn.