Deserves its own thread...
When I worked in the industry (site acquisition & zoning) I ran through several of the major brands of phones. Coverage is, frankly, an interesting concept or theory, not a fact. E.g. with "push to talk" carrier: co-worker and I had zero connectivity in adjacent vehicles waiting at a RR xing. A FRS walkie-talkie would have worked better. And I found out first-hand how fictional those coverage maps really are.
During the big black-out of a couple years back, text messaging worked, but conversations did not. As I understand it, a call uses more resources than a text message. So when I'm in a "no cell phones" zone, say, in a hospital waiting room telling my far-flung sibs some new detail about the aforementioned 80yo parental unit, I can text them, send them all the same message, and it goes through.
If Marlys' son and DIL had phones, they might not have been able to call for help from their stuck location. However, once Tina got out, she'd have had coverage (and battery charging capability, presumably) and could have called or texted hubby or daughter. The phone she found worked, so presumably at least one carrier had coverage in that area. If one of them got out to Towerland, s/he could leave a message for the other, who could recieve it once s/he got out.
This is a lot of armchair quarterbacking, but I have found my phone to be incredibly useful. Agree with comments about the clueless using a phone as a rescue device.
Marlys, I have been channelling OnStar commercials lately. I'm sure that's a good sign. Can they put out an Amber Alert for DS?
HTH
--Karen M.