What number should be called to notify authorities in an emergency?

The number to call in an emergency is 911, which is designated as the primary emergency telephone number in the United States and many other countries. This number is intended for situations that require immediate police, fire, or medical assistance. When someone calls 911, the operator can quickly assess the nature of the emergency and dispatch the appropriate services.

In contrast, the other numbers listed serve different purposes. For example, 411 is typically used for directory assistance or finding information about phone numbers and addresses, while 311 is often used for non-emergency municipal services and general inquiries. The number 123 is not a recognized emergency number in most jurisdictions.

Understanding the specific purpose of these numbers is crucial for ensuring that help is obtained quickly when needed, highlighting the importance of calling 911 in emergencies to facilitate a rapid response from emergency services.