Tauranga Adventist School principal Ross Bishop was left scratching his head when he arrived at work yesterday.
The Moffat Rd school's brand-new shade sails, worth $18,000, had been destroyed.
Steel ropes holding up the sails had snapped, leaving them "in tatters".
"We were very, very puzzled. We couldn't understand it, we weren't aware of any strong wind.
"It was obviously a huge force. We didn't have a clue as to what caused it," Mr Bishop said.
Mr Bishop checked the Bethlehem school's weather station, which reported winds of 45km/h about 6pm - not enough to cause such extensive damage.
But the mystery was solved when a parent phoned the school after reading yesterday's Bay of Plenty Times.
A small twister had hit Hairini on Wednesday night, lifting off a shed roof and sending it flying across SH29.
Damage was also done to fences and trees, and steel poles bent. But the twister was so localised that other parts of the property were untouched.
Mr Bishop believed the school was victim of the same or a similar twister.
Now, the school must replace the shade sails, which had not even been paid for yet.
Mr Bishop couldn't believe the damage caused.
"It's quite interesting - usually these things create quite a bit of a trail, but not in this case."