Mass shootings in U.S. history

Published On: Jul 20 2012 09:20:30 AM CDT   Updated On: Apr 03 2014 07:39:55 AM CDT
Fort Hood

A gunman opened fire at the Fort Hood military post in Texas on Wednesday, killing three people and wounding 16 before committing suicide. Take a look at some of the worst mass shootings in U.S. history.