Bomb shelter

An air raid shelter is a structure built to protect against bomber planes dropping bombs over a large area.

A bunker may be hastily assembled as part of an ongoing military advance, or to hold a line.

While military units have long built defensive structures to protect against various kinds of hostile bombardment, the use of the phrase "bomb shelter" can be traced at least as far back as 1833.

[2] In 1881, the United States War Department issued a report in which it indicated that the defenses of Charleston, South Carolina included construction at Fort Moultrie of: ...eleven permanent gun-platforms and breast-height walls, bonnets on the traverses, a portion of the masonry and all the earth covering of the bomb-proof shelter, the postern gallery, a part of the earth covering of the magazines, and an earthen cover face on the channel front.

[3]The shortening of this phrase to the conventional "bomb shelter" appears in print at least as early as 1895.