Facebook's Safety Check feature isn't that new, being introduced in October of 2014, but it was new to me. I am lucky where I live now. We just don't get these kinds of massive natural disasters. Not that Safety Check is only activated during natural events - in November 2015 it was activated for the attacks in Paris as well.
The beauty and importance of the Safety Check is in the simplicity. When there is an emergency situation going on social media gets flooded with people checking up on each other, but this can get overwhelming. The Safety Check system allows people to reassure everyone on their lists with the hit of a button. After a disaster the system is activated and everyone that is listed as being in the affected area can mark themselves as safe (or not in the area at that time) and all of their friends will get a notice that they are safe.
It's been 3 years since I lived in Taiwan, but I still have friends there I care about (and I still dream of the day I can go back and see them). The speed at which I knew all of them were OK was utterly amazing. Before the end of dinner that very night, within 5 hours of the earthquake happening, all but one of my friends had checked in.* Facebook saved me from at least one sleepless night - if not more - and the stress and fear of not knowing. I have never liked having Facebook as much as I did that night.
*That one friend that didn't check in ... he seldom uses social media, so my guess is that he doesn't even know about Safety Check. I'll be sure to have a talk with him about that later.