Starting Thursday, emergency call centers across Maryland can receive and respond to text messages sent to 911.
The state says if you can't make a voice call to 911 because of a disability, medical emergency or unsafe situation, you can instead type out a message.
The service is open to AT&T, T-Mobile, Verizon and former Sprint customers with text message or data plans. Both visitors and residents can text 911 in an emergency.
Here's how it works: Enter 911 into the "to" line of your text message. Type a brief message and include your location and what type of help you need (fire, emergency medical services or police).
After you hit send, a specialist will respond. Be ready to answer questions or follow instructions.
If the service isn't offered in your area or it's temporarily unavailable, you should get a text telling you to call 911 by phone.
It's preferable, but not required, to text in English because translation services for texting may vary between areas, the Maryland Association of Counties says.
Montgomery and Prince George's counties both have translation services on standby for emergency calls.
Don't send photos, videos or add another contact to the conversation with 911: It could prevent your message from being received.
It's a good idea to call if you can, partly because text messages can arrive slowly or sometimes fail to arrive at all.
Text-to-911 is meant to be used in three scenarios, the Maryland Association of Counties says: For those who are deaf, hard-of-hearing or have a speech disability; when it's unsafe to place a voice call to 911 and for those experiencing medical emergencies that make them unable to speak.
Both Virginia and Washington, D.C., already offer text-to-911 services.