In the case of a natural disaster, such as flood or earthquake, making a phone call might be out of the question and so we may turn to social media or to be more precise the micro blogging site Twitter! It is amazing how much detail can be put into a short message and once it has been posted its there for all to see.
This was the basis of Lifeline, a feature that Twitter created in order to assist Japanese users during an emergency situation. Now Twitter are introducing Twitter Alerts with the view to allowing people to warn others of natural and emergency situations, when other means of communications are unavailable.
In order to set up the Twitter alert, simply visit the organisations Twitter Alert Page to activate this service with your account. You will need Twitter for iPhone version 5.10 or higher and Twitter for Android 4.1.6 or higher in order for this service to work properly.
Source: Twitter Blog