The twin towers of the World Trade Center billow smoke after hijacked airliners crashed into them early 11 September, 2001. Henny Ray Abrams/AFP/Getty Images hide caption

itoggle caption Henny Ray Abrams/AFP/Getty Images

Kelly Thompson, a mentor at Siemens, gives apprentices an orientation of the factory. The program provides on-the-job training in manufacturing. Courtesy of Siemens Energy Inc. hide caption

itoggle caption Courtesy of Siemens Energy Inc.

Two students walk in front of Stanford Memorial Church on the Stanford University campus in Stanford, Calif. Paul Sakuma/AP hide caption

itoggle caption Paul Sakuma/AP