If you happen to hears sirens, and witness a flurry of activity by fire appliances and police vehicles in the vicinity of City of Derry Airport (CoDA) tomorrow, don't worry they're only training.
An emergency training exercise is scheduled to take place at the facility from 12.30 p.m. to 4 p.m.
The PSNI, NIFRS, HMCG and Foyle Search & Rescue will take part.
"The purpose of the exercise is to test CODA’s emergency and safety capability," the airport said.
"The airport will be running the exercise outside of normal operational hours. The public can be assured that emergency Fire & Rescue cover will not be affected during this time.
"We thank the public in advance of this exercise for their co-operation, with disruption to the public being kept to a minimum," it added.