People comfort each other as they sit near the scene Thursday, Nov. 8, 2018, in Thousand Oaks, California where a gunman opened fire Wednesday inside a country dance bar crowded with hundreds of people.
Sheriff Geoff Dean of Ventura County police said at least six off-duty officers were at the bar, which was hosting a country music night.
Police have named the suspect in Wednesday's attack as 28-year-old Ian David Long, a US Marine Corps veteran with suspected PTSD (post-traumatic stress disorder).
Cody Coffman, 22, was among the dead after a gunman opened fire in a Californian bar.
Mr Dean said his department had several previous contacts with the former Marine including a call to his home in April, when deputies found him acting in an irate and irrational manner. No other information on the victims was immediately known.
Ron Helus, a Ventura county sheriff's sergeant, was among those killed at the Borderline Bar and Grill, about 40 miles west of Los Angeles.
Survivors described moments of panic and heroism.
Authorities found the gunman dead inside an office adjacent to the bar's entryway, Dean said.
"I mind my own business and they did theirs too", he said in a brief telephone interview.
A friend, Sgt. Eric Buschow, said Helus took on some of the toughest assignments, was on the SWAT team for much of his career and worked in narcotics and investigations.
Then, he said, he and others pushed down the broken glass and helped about 30 or 35 people out.
Erika Sigman, 19, was another witness. She said she hid with a group of strangers and they were holding hands.
"I saw someone throw a bar stool through the window and I followed suit and I threw a bar stool through the window and we just pushed people towards the bar, so that they weren't in the direct line of sight of him and then just filed as many people, everyone that was there, out through that back window", he explained.
KNBC-TV spoke to a man at a reunification center which had been set up for families. Hours into the tragedy no one had been reunified with a loved one. Coffman broke down as he told reporters how his last words to his son as he went out that night were not to drink and drive and that he loved him.
Before he responded to the shooting, Wednesday night was like any other busy night for him, backing up fellow deputies on every call that he could, VCSD Senior Deputy Julie Novak told CNN affiliate KCAL/KCBS.
"How ironic that my son should be killed this way", Orfanos said.
Helus was not only a 29-year sheriff veteran, but he was also a husband and father.
Dean said he believed about 150 to 200 people were inside the bar at the time of the shooting.
A bomb squad was combing through the scene early Thursday morning after some witnesses reported that smoke bombs went off during the gunfire.
California Lutheran University canceled classes Thursday following the shooting. The university invited the community to gather at the school's chapel. The bar is near the campus.