9-1-1 should be used in any situation that requires immediate assistance from the police, the fire department or an ambulance. If you are ever in doubt of whether a situation is an emergency, you should call 9-1-1. It's better to be safe and let the 9-1-1 call taker determine if you need emergency assistance.
On July 20, 2015 the Montgomery County Commissioners announced that wireless phone customers have the ability to send short text messages to 9-1-1 in an emergency. At this time, Text-to-911 is only available to subscribers of AT&T, Sprint, Verizon Wireless and T-Mobile.
Text-to-911 may be most helpful in these emergency situations:
By individuals who have speech or hearing impairments, or who are having a medical emergency that renders them incapable of speech;
Or in instances when making noise may endanger the caller, such as a home invasion/robbery, or instances of domestic violence or an abduction.