WASHINGTON: Martyl Langsdorf, an artist who designed one of the most enduring visual images of the 20th century, the Doomsday Clock, with its hands ticking toward midnight as a symbol of impending nuclear destruction, died March 26 at a rehabilitation facility in Schaumburg, Illinois She was 96. She had complications from a lung infection, her daughter Suzanne Langsdorf said.

Langsdorf was already a successful artist by the time she was asked to design the cover of the June 1947 issue of the Bulletin of the Atomic Scientists. Against an orange background, she set a quarter of a clock face, with a black hour hand pointing to the “12” position as a white minute hand approached 11:53.

Even without the accompanying articles about the danger of nuclear weapons, the implication was clear: The fate of the world was in doubt unless an escalating arms race could be stopped before it reached the doomsday hour of midnight.

“It’s such an intuitively tension-building image,” graphic designer Michael Bierut, who updated Langsdorf’s design in 2007 and is on the board of the Bulletin of the Atomic Scientists, said Saturday in an interview. “To be able to reduce something that complex to something so simple and memorable is really a feat of magic.”

It was the first and last magazine cover that Langsdorf designed.

Two years later, in 1949, the Soviet Union tested its first nuclear weapon, and the Cold War began in earnest. The scientists who guided the bulletin — including Langsdorf’s husband, nuclear physicist Alexander Langsdorf Jr. — reconfigured the image of the Doomsday Clock by moving its hands four minutes closer to midnight.

In one stroke, Langsdorf’s design had been reinvented as a wide-reaching symbol of the age. A powerful idea was expressed in a visual image containing four dots and two lines.

“The scientists decided to use it imaginatively as a metaphor,” Bierut said. “That’s really a complex thing. “To wed this almost childish cliche to this fear of the annihilation of the Earth, that’s really remarkable.”

During World War II, Alexander Langsdorf had helped develop the atomic bomb as a member of the Manhattan Project. After bombs were dropped on Hiroshima and Nagasaki in Japan, leading to the end of the war, he began to have misgivings. He was one of about 70 scientists who signed a letter to President Harry S. Truman, pointing out the “solemn responsibility” of the United States to control the use of nuclear arms.

Langsdorf’s simple visual image entered pop iconography as an element in songs by the Who, Iron Maiden and Bright Eyes. It was featured in novels and nonfiction books and became a near-universal symbol of the dangers lurking in the modern world.

Langsdorf was resigned to being known as the “clock lady,” but she liked to point out that she had an 80-year career as a painter and printmaker. Her art was included in exhibitions at the Art Institute of Chicago, the Los Angeles County Museum of Art, the St. Louis Art Museum and other prestigious venues.

Her work, which consists largely of landscapes and still lifes, is in the permanent collections of many museums, including the Smithsonian American Art Museum and Hirshhorn Museum and Sculpture Garden in Washington. At the time of her death, she was preparing for a new gallery exhibition in Chicago.

Since 1947, Langsdorf’s Doomsday Clock reappeared often on the cover of the Bulletin of the Atomic Scientists, reflecting the changing state of the world.