More people appear to be falling victim to distracted walking.  A new study shows the number of people injured or killed while walking around with headphones on has tripled since 2004.  The study shows 47 pedestrians were injured or killed while blasting tunes between 2010 and 2011. That's compared to only 16 people between 2004 and 2005.  Researchers say roughly half of the victims were hit by trains, while the other half were hit by vehicles or bicycles.  The study appears in the journal "Injury Prevention."