Ten people working at a farm in County Londonderry had a lucky escape after what they described as a tornado struck it on Wednesday afternoon.
It ripped the roof off the barn. A car was also destroyed when a wall collapsed on it.
Farmer Fergie Kelly, said the workers were trimming cows' feet in the barn near Eglinton, when they heard a bang.
"We thought there was a bomb that went off. We ran out of the shed.
"The cows all stampeded ... We saw a tornado going down through the field. The tin was hurled into the air, along with the roof trusses and blocks and a lot of other debris. It was quite a scary experience."
Mr Kelly said no-one was hurt but they were "totally scared" by their experience.
BBC weather presenter, Cecilia Daly said the last couple of days had brought some unusual types of weather to various parts of Northern Ireland
"We have had torrential rain, thunderstorms, massive hail, and on Wednesday there was a report of a tornado near Eglinton around lunchtime," she said.
"The weather team received pictures of a funnel cloud from one of our storm chasers, Martin McKenna, and a tornado is basically a funnel cloud which makes contact with the ground and as result will sweep up anything in its path depending on how much energy is available and therefore how powerful the 'twister' is.
"Unfortunately we do not have any pictures or footage of the event and although atmospheric conditions were favourable for a tornado on Thursday, the damage may also have been caused by another weather related feature such as a gust front.
"If the wind following a gust front is intense and damaging, the windstorm is known as a downburst.
"This is less dramatic than a tornado, but still powerful in terms of the damage caused and very frightening for those who witnessed the experience."
"The shed roof started to lift and all of a sudden the shed roof lifted off into the air," he said.
"The only good thing about today is everyone got out without being hurt."