Four Marines killed in two US military shootings

At least two people were injured during the incidents in Chattanooga -- a police officer and a Marine Corps recruiter. The gunman was shot dead, city mayor Andy Berke told reporters. The incident served as an ugly reminder of other deadly shootings at US military installations, including a 2009 rampage at Fort Hood that left 13 dead and a 2013 attack at the Navy Yard in Washington that left 12 dead.