THOUSAND OAKS, California - The gunman who killed 13 people at a bar in Southern California was a Marine who served one combat tour in Afghanistan, and was last stationed in Kaneohe Bay.

Officials say 28-year-old Ian David Long opened fire during a college night at a country music bar in Thousand Oaks Wednesday night, killing 13 before taking his own life.

The Marine Corps says they, "Extend [their] deepest condolences to the families of the victims in this senseless tragedy."

They also say Long was deployed to Afghanistan for seven months. He served as a machine gunner and earned the rank of corporal in August 2011.

In Kaneohe Bay, he was assigned to the 2nd Battalion, 3rd Marine Regiment, Third Marine Division. 

Long was also served divorce papers while in Hawaii, back in 2012.

Flags will fly half-staff at the State Capitol and agencies, as well as the Hawaii National Guard in the State of Hawaii as a sign of respect for the victims.

“My heart breaks for the families of the victims of this tragedy, and I am hoping for a speedy and complete recovery of those who were injured. Hawaii’s connections to California are strong, and we grieve along with the Thousand Oaks community,” said Gov. David Ige.

President Donald Trump shared his condolences via Twitter.