An investigation is underway into a fire at the old Herdmans Mill in Sion Mills.
Over 60 fire fighters and 9 appliances spent hours at the scene yesterday afternoon, some remaining there until late last night to keep the blaze under control.
The cause of the fire is not yet known but police in Strabane are investigating the incident.
No injuries have been reported.
Local Councillor Patsy Kelly believes the fire was started deliberately: