As a recent survivor of Hurricane Ian that plowed through Florida, and also as a long-time user of the Zello app (for several years now), I paid close attention to an article by Charity Blanton published in the WPSD web site: 

Millions of people in the path of Hurricane Ian are still without power.

With many cell towers down or inoperable, it's extremely difficult for the people who need help and the people who want to help to communicate.

Cellular companies are rolling in temporary portable cellular towers to provide at least some connection to the internet, but these towers often cannot meet the demand of customers. Rescue departments and volunteers have turned to a smartphone app as a solution.

Zello is sort of like a walkie-talkie app, allowing users to send audio and text messages to one another even in areas with limited cell service. Many rescue agencies use Zello to communicate with each other. Volunteers use Zello too — Cajun Navy Relief is using it right now to help in Florida.

Cajun Navy formed years ago during Hurricane Irma and began using the Zello app as its sole communication tool. The community currently has volunteers reviewing requests for help and mobilizing volunteers across the country. It's pretty amazing to listen to their Zello channel as people from Texas, Virginia, Arizona, and other states far away from Florida log on to review requests or tickets from victims of Hurricane Ian.

The article goes on for a bit longer at: https://tinyurl.com/ykepym6t.

I strongly agree and recommend Zello. I recommend you install it on your cell phone. You may never need it. Then again, maybe you will. The app is free for iPhones and Android devices.