I'm sorry, I'm New to plumerias. You can grow them from the cuttings? If so, what's the general process please... I'd like to learn more.

Sorry to hear about your setback but you did the right thing and hopefully you're on your way to them recovering! It's happened to all of us so I understand the disappointment :( Good catch though, at least you have a chance at saving them!

b_byrd - the basics are to get a cutting, make sure it has a good callous on it and get a smaller container such as a water bottle, Gatorade bottle, etc (then you'll be able to see the roots if it takes) or some people water root it then transfer to soil. If rooting in a bottle type container make sure you drill drainage holes too & you'll use a well draining soil or cactus mix, stake it up, water it really well once, keep it warm & then pretty much leave it alone until you see roots. That's just a short version, you can search and find many threads on this topic for specifics and different techniques. If you decide to give one a try we can always try to answer specific questions if you can't find the answer you're looking for.

looks to me like sudden cold exposure... its that sensitive you know.

I think there were a few things that probably brought it on. The day I planted them in the big pots it went from warm and sunny to freezing rain downpour (I sleep during the days so I didn't catch it in time) and everyday after rained like crazy while I was at work so even though they were in a protected area, it wasn't protected enough. After that it was quite warm and dry, but... by then the damage was probably done. Either way, I'm being uber protective of them now! The little containers I have them in do have hole at the bottom and they're staying nice and warm and dry (for the most part).