Kara Kennedy died of a heart attack on September 16, 2011, at the age of 51, after her daily workout at a Washington, D.C., health club. She had been diagnosed with lung cancer in 2002 and underwent surgery, chemotherapy, and radiation treatment, which her brother Patrick Kennedy said physically weakened her. It is believed that the aggressive cancer treatment may have damaged her heart, leading to the fatal heart attack. Despite having fully recovered from cancer and leading an active life, the toll of the treatment on her heart was significant enough that her heart gave out during exercise.
