911

911 is the emergency telephone number used in the United States, Canada, and several other territories to request police, fire, or medical assistance. It is a three-digit number designed for rapid recall, dialed from landlines or mobile phones. When dialed, the call is routed to a Public Safety Answering Point (PSAP), where trained telecommunicators assess the situation and dispatch appropriate responders.

The system's origins lie in mid-20th century efforts to standardize emergency access; the first 911 call was made on February 16, 1968, in Haleyville, Alabama. Over time, the U.S. and Canada introduced Enhanced 911 (E911), which automatically provides the caller’s location and phone number to the PSAP. In recent decades, Next Generation 911 (NG9-1-1) has been rolled out to support digital information, including texts, images, and video, and to route calls using IP-based networks.

Usage and limitations: In most areas, 911 services handle police, fire, and medical emergencies. Wireless 911 uses location triangulation to determine the caller's position; in some cases, location data may be inaccurate. Text-to-911 is available in many, but not all, jurisdictions and may not support multimedia. For non-urgent matters, many regions provide non-emergency numbers.

Global context: 911 is not universal. Other countries commonly use 112 or 999 as emergency numbers. The digits 9/11 are also associated with the September 11, 2001, terrorist attacks in the United States, a separate use of the digits.