Loss is defined as taking place at a known time, in a known place, and from a known cause. A common example is the death of an injured person who has taken on a life insurance policy. Incidents like fires, car accident, and work-related injuries may all easily meet this criterion.
Other types of losses are subject to different criteria and are often only definite in theory. Occupational disease, for example, may sometimes involve prolonged exposure to hazardous conditions, thus resulting in no specific time, place, or cause identifiable.
Ideally, the time, place, and cause of the loss should be objectively verifiable by a reasonable person, provided there is sufficient information.