Beginning Thursday, those needing to contact 911 for an emergency will now be able to send a text message. This could be especially useful for someone who is deaf, hard of hearing or in a dangerous situation where calling 911 isn't possible.

The four major cellular providers -- AT&T, Verizon, Sprint and T-Mobile -- agreed to participate in the Federal Communications Commission program. The FCC made Thursday the deadline for call centers to get the capability of receiving text messages. Not all cities and towns will offer the service.

"Access to 911 must catch up with how consumers communicate in the 21st Century," Julius Genachowski, the former chairman of the Federal Communications Commission, said when the "text-to-911" plan was first proposed in 2012.

Any phone capable of sending a text message will be able to send a 911 text. If the call center nearest to where the text is being sent from is set up, they will receive the message. The person sending the text message will need to provide their location because location services aren't available with 911 texts.

Right now, officials recommend using 911 voice calls because they are much better at locating where the person is calling from. But, there are times when calling 911 just isn't possible.

"It's always preferable to make a voice call to 911," Trey Forgety, director of government affairs at the National Emergency Number Association said. "Call if you can, text only if you can't."

Text messages aren't always instant either. The caller could be in a bad cellular area and the text may not always go through. If that happens, they will get a "bounce back" message saying the text was not delivered.

In the next six months, more cities and towns are expected to join onto the 911 text services, but it could take years to get it fully implemented.

Here is a frequently asked question section from the FCC.