Two years ago, a 9-year-old girl accidentally shot and killed instructor Charles Vacca with an Uzi gun at a shooting range. Now his family is suing the gun range, operated by Bullets and Burgers, for wrongful death. Elizabeth Vacca, 17, and her brother, Christopher, 12, tell CBS News why they are calling on lawmakers to pass legislation in regards to assault weapons and children. See the Vacca family's petition to lawmakers.