Next, largest dangers in my area are wars, and wars happen with a disturbing regularity. In wars, the primary use of this is, as I see it, is doc**entation of potential war crimes. More solid evidence could help later convict war criminals and serve as a warning to those who might want to repeat that side of war later.
However, I'm personally more worried about earthquakes. Particularly because for several last decades, earthquake safety regulations in construction are almost universally ignored. If someone gets caught in one of the newer residential buildings, his chances of survival in case of a structure collapse (and that is more likely with newer structures), is slim because there are no pathways for rescue parties to come trough the rubble.
Older buildings were built with some clearance around them allowing free movement for the rescuers.
First of all, the list of resources and people on site willing and able to provide aid is needed, next we need to know where people are in trouble to put those two together.
Reminder: carry a whistle, it can save your life. You can also use it to communicate with other people on site.