In the wake of the deadly Sevier County wildfires, there has been discussion of the warning system in place.

RELATED: NWS: Sevier Co. evacuation notification system complicated

Some people have reached out to 10Listens, asking about warning systems in other East Tennessee counties.

When disaster is approaching, how do local leaders notify people and tell them how to stay safe?

First, through FEMA, all counties in the US have access to something called the Integrated Public Alert & Warning System.

Through IPAWS, counties can use the Emergency Alert System, which broadcasts over TV and radio. They can also send a Wireless Emergency Alert, with authorization from state emergency management officials.

RELATED: Evacuation notices for Gatlinburg, Pigeon Forge never sent to mobile devices

However, some counties opt for additional methods of emergency notifications.

10Listens reached out to several East Tennessee counties. We didn't hear back from all of them Tuesday, but we learned at least two counties, Monroe and Loudon, use a system called Hyper-Reach.

That's a private company that contracts with counties, cities - even college campuses - and allows leaders to call any landline with an emergency message. People in that county (or city or campus) who want a text message or call on their cell phones have to sign up with the service.

10Listens also learned Jefferson County contracts with a similar service called Nixle, which is also an opt-in notification system.

And Morgan County, like Sevier County, uses a service called CodeRED, for which residents must sign up.

WBIR 10News asked Sevier County Emergency Management how many people are signed up for the county's CodeRED notication system and whether it was used last Monday night. The director replied, saying they're still working on the sequence of events from that night.

A "last resort," Loudon County said, "is public address systems on fire and police vehicles in an affected area."

In addition, Tennessee code requires each county to have what's called a Basic Emergency Operations Plan (BEOP), which TEMA must approve.