BJ Leiderman is the composer of the theme music heard on NPR's Morning Edition, Weekend Edition and Wait Wait...Don't Tell Me! Courtesy of Cole Rian: Jen Haynes & Mel Wils hide caption

itoggle caption Courtesy of Cole Rian: Jen Haynes & Mel Wils

Brothers Tom (left) and Ray Magliozzi pose under a car hood in Boston. The comic duo hosted NPR's Car Talk for a quarter of a century before retiring in 2012. Since then, the show has been heard in reruns. Tom has died at age 77. Susan Walsh/AP hide caption

itoggle caption Susan Walsh/AP

Tom Magliozzi's laugh boomed in NPR listeners' ears every week as he and his brother, Ray, bantered on Car Talk. Courtesy of Car Talk hide caption

itoggle caption Courtesy of Car Talk

After the bombs went off Monday in Boston, bystanders, police and emergency personnel rushed to help those who were caught in the blasts, as this video image shows. Marc Hagopian/AFP/Getty Images hide caption

itoggle caption Marc Hagopian/AFP/Getty Images