What happens when you call 911

Hello operator, get me an ambulance!
Before the 1970’s it was not always easy to get help in an emergency. Fire, police and ambulance services often had different phone numbers. People would call their doctor or the local police department for a medical emergency. To address the problem, the Federal Communications Commission and public safety officials worked with telephone companies to create a universal three-digit number for all emergencies—hence the 911 communications system was born.

The first 911 call in the US was made in 1968 but it took years to get 911 established throughout the country. Some urban areas had the first 911 services by the mid-1970’s but 911 was not widely available until the 1980’s. (1)

Today we know time is of the essence for a victim of a sudden cardiac arrest. A quick response, by both bystanders and healthcare professionals, is needed to give the best chances of survival. 911 is a critical part of that response.

Emergency medical dispatchers
In most cases, your call to 911 will be directed to the closest 911 communications center. Some 911 centers handle only police or fire emergencies. Your call may be rerouted to a center that handles medical emergencies. If that’s the case, stay on the line while the emergency operator relays the information you provided to the medical 911 center.

Calls for medical emergencies are handled by an emergency medical dispatcher (EMD). The EMD will verify your address, gather basic information on the patient and send appropriate personnel to respond.

The EMD first will ask you for basic call information including your location, telephone number, location of the patient and the general nature of the problem. In many cases, a second EMD will dispatch emergency responders while the first continues to ask you questions about the victim. The goal is to get responders moving as soon as possible, once the basic information is known.

Next, the EMD will ask a series of questions to determine the severity of the situation. EMDs ask specific questions so they know what help to send and which care instructions to give. One of the first things the EMD will want to know is whether the patient is conscious or breathing. “An EMD’s job is to triage your call to determine what resources the situation requires," says Cleo Subido, Emergency Medical Dispatch Program Administration with King County EMS in Seattle, WA. This assures that the right personnel and equipment are sent to the scene and time is not wasted.

EMDs are trained to quickly gather information. Try to answer all questions as best you can. Remember, emergency scenes can be chaotic and there may be lots of distractions. Try to be calm and speak clearly.

The EMD is responsible for relaying information to the responding personnel so they are prepared when they arrive at the scene. If there is any information you think might be important, provide that to the EMD. This will help him or her decide if special equipment or specially-trained personnel are required, for example, drowning or special rescue situations. "They want to send you timely help and the most appropriate help so it is important to stay on the line and answer all the questions," says Subido.

Be aware that the EMD may call you back to clarify the exact location of the patient, ask you to direct a bystander to meet the ambulance or direct emergency medical services (EMS) crews to the patient. In addition, the EMD’s job is to coordinate requests from the EMS crew to dispatch support resources, such as police, additional ambulances, rescue equipment or a helicopter.

Using a mobile phone in an emergency
The FCC requires all wireless phone carriers to route 911 calls to an emergency call center. This includes phones that have never established service or whose service has expired. (2) In addition, if you have Enhanced 911 (E911) service, it sends your mobile phone number and the location of the nearest cell tower. A majority of mobile phones with E911 today provide even more precise location information (within 300 meters) such as latitude and longitude or through triangulation between radio towers. (3)

Even if you are traveling in a car, 911 will connect you to an emergency call center as long as there is adequate reception. Let’s say you are driving on a rural freeway and you come across an automobile accident. You dial 911 on your mobile phone. In many cases, your call initially will be routed to a state patrol 911 center. These centers do not usually dispatch EMS or fire department crews. They will immediately transfer your call to the nearest 911 center that can dispatch an ambulance or fire crew to your location.

What might a 911 dispatcher ask me to do?
Many emergency dispatchers are trained to guide you in assisting with basic first aid. You may be given instructions for CPR, choking, emergency childbirth or bleeding control. These are things you can do to help the patient before the arrival of EMS. Note that, in some rural areas, the local 911 center may not provide medical instruction. They may just ask for your address and what type of help you need without asking further questions.

How 911 has changed over the years
911 has evolved over the last thirty years. Emergency dispatchers now give instructions in performing lifesaving maneuvers such as CPR and assisting a choking victim. So-called “dispatcher-assisted CPR” is available in most metropolitan areas.

E911 systems that display the caller's number and address to the 911 center are active in 93% of US counties. (4) Most cities have E911 systems in use. E911 includes cell phones which are tracked to the closest cell tower. There are ways to calculate a location more precisely, but you should be prepared to give the dispatcher a mile marker, street intersection or landmark when calling from a mobile phone.

Coming in the future is next generation 911 which will allow you to send text, pictures, and videos to 911 centers. This will be helpful for those who are hearing-impaired. Also, witnesses at the scene will be able to electronically send a picture of accident or a suspect picture.

The modern 911 system makes it easy to connect to the public safety professionals who can help you in an emergency. You should always call 911 immediately when you find someone who is unconscious and unresponsive.

When the 911 dispatcher answers you'll be asked your location, address and what the problem is. One of the first things they will want to know is whether the patient is conscious or breathing.

Once the basic information has been collected by the dispatcher, someone at the 911 center quickly will contact EMS and appropriate resources. While you are on the phone the dispatcher may ask you a few more questions about the patient’s condition. This information will be relayed to the responding unit(s).

NOTE: In some buildings, you must call your organization's security number instead of 911. Know your organization’s rules for getting help in an emergency.


1. The Briefing Book. Dispatch Magazine On-Line. http://www.911dispatch.com/info/fact_figures.html (accessed May 22, 2013).

2. 911 Wireless Services. Federal Communications Commission. http://www.fcc.gov/guides/wireless-911-services (accessed May 28, 2013).

3. Enhanced 9-1-1. Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Enhanced_9-1-1 (accessed May 28, 2013).

4. 9-1-1 Statistics. National Emergency Number Association. http://www.nena.org/?page=911Statistics (accessed May 22, 2013).