The Grayson County Sheriff's Office is advising Tioga, Collinsville, Pilot Point and Trenton residents in need of immediate emergency assistance to use a cell phone when dialing 911 Wednesday, amid possible outages affecting landline service.

In a social media post published Thursday morning, the GCSO said the outage is the result of a severed fiber optic cable. Landlines may be affected and residents may be unable to receive or place calls. It wasn't immediately clear Thursday morning when landline service might be restored.

The Sheriff's Office encouraged residents living near the affected to remain aware of the outages and their current location in case emergency services are needed.

“Knowing your location when calling 911 from a mobile device will save valuable time,” the agency's post read. “Also, remember you can also text 911, if you are unable to call from a mobile device.”