The turbine was one of eight Nordex N80 2.5MW units, which comprise 60m towers and 80m rotors.
Following the collapse, seven of the eight turbines have been shut down and officials are working with Nordex UK to ensure the site is safe.
Screggagh Windfarm director Doreen Walker said: "There were fortunately no injuries and no personnel on site at the time.
"We are currently investigating the circumstances that led to the collapse of the turbine at Screggagh wind farm."
"A further statement will be made once the investigation has been completed and the reasons for the failure confirmed."
The Screggagh wind farm is capable of delivering enough energy for about 10,500 households per year and the average wind speed at the site is 8.5 m/s.
