Evacuation refers to the act of removing people or objects from a particular place, usually due to danger or an emergency situation. It can also refer to the emptying of something, such as a container or a body cavity. In the context of natural disasters, evacuation is often used to describe the process of getting residents and visitors out of harm's way before, during or after a catastrophic event like a hurricane, tornado, wildfire or earthquake. This can involve ordering mass notifications through various means such as sirens, text messages, phone calls or public address systems to alert people about the danger and instruct them on what to do next.