The stark insignia of civil defense — a C and D forming a red circle in a white triangle on a blue disk — died yesterday after a long eclipse. It was 67 years old and lived in the mind’s eye of anyone who remembers air-raid drills, fallout shelters and metal drums filled with what had to be the stalest biscuits in the world.

Its demise was announced by the National Emergency Management Association, the group that represents state emergency managers.

The CD insignia, which the association called “a relic from the cold war,” was eulogized by Richard Grefé, the executive director of the American Institute of Graphic Arts.

“The old mark fits in the same category of simplicity and impact occupied by the London Underground map,” Mr. Grefé said.