Definition - What does Unfriendly Fire mean?
An unfriendly fire (also called a hostile fire) is a combustion that is uncontrollable and has moved out or spread from its original location. It may also refer to a combustion that happens where it should not. This is a peril that can be covered by insurance.
Insuranceopedia explains Unfriendly Fire
The term is the opposite of friendly fire, which is a fire that happens where it is expected to happen, like in a fireplace or a cooking stove. An unfriendly or hostile fire, then, is one that happens in unlikely areas, such as a garage or a room that doesn't typically contain a source for fire.
The damage that an unfriendly fire causes can be covered by a commercial liability policy. For the damage to be covered, however, it must be directly traced back to the unfriendly fire.