army psychiatrist major nidal hasan opened fire on november 5 , 2009 , killing 13 men and women at the military post in killeen , texas , injuring 30 others before he was shot himself .
authorities initially classed the mass murder as ` workplace violence ' but it has since been acknowledged that the attack was an act of terrorism .
earlier this year , it was ruled that victims will be honored with purple hearts - awarded in the name of the president to those wounded .