Letting all of your loved ones know you're safe during Irma could be as easy as posting on Facebook. Actually, that's exactly what you have to do.

If enough people post about an event, according to Facebook, then "Safety Check" will be activated during your own post.

Facebook says users will then be prompted to go to "Safety Check" to left everyone know they're safe during a crisis.

Safety checks started popping up for Irma a few days ago and continue to flow in.

Once users let their Facebook friends know they're safe, they invite others to use "safety Check" and can provide or find help.