Professors Patricia Fehling (left) and Denise Smith are using a federal Department of Homeland Security grant to determine why heart attacks are the major cause of firefighter death. They've enlisted the help of the Oxnard (Calif.) Fire Department to learn more about this puzzling killer. Thu, 25 Jun 2009 16:00:00 -0800 ,, Thu, 25 Jun 2009 16:00:00 -0800