cell broadcast for real emergencies texts through registration on the site of the city hall, if cell braodcast isnt implemented by the phone company public em

cell broadcast for real emergencies texts through registration on the site of the city hall, if cell braodcast isnt implemented by the phone company public emergency sirens radio TV actual website of the city hall local newspaper social fabric, with residents actually calling each others, for non emergency topics ? (Hacker news ?) Twitter has never been a great solution on its own. It could have contributed along with other channels of communication, so you should already have these.