美国有线新闻 CNN 美国加州一酒吧发生枪击事件 枪手有精神健康问题（在线收听）

We have some tragic news to tell you about first today. It involves a shooting at a bar in Thousand Oaks, California.

Here's what we know. It took place on Wednesday night at a place called Borderline Bar and Grill. Students from California Lutheran University and Pepperdine University are believed to have been there at the time. Officials estimate hundreds of people were. Police say a gunman forced his way into the bar and started shooting with a single handgun. A Ventura County Sheriff says officers got to the scene within three minutes after the first emergency call was made. Two of them went into the bar after hearing shots, and one of them, a law enforcement veteran, was killed.

At least 11 other people died in the incident, including the suspected shooter. Police believe he killed himself. What they don't know is why this happened. Police say the gunman was a 28-year-old military veteran. He had had run-ins with police before. A sheriff says a crisis team that visited the suspect in the past thought he might have had post-traumatic stress disorder, possibly from the time he served in combat.

The mayor of Thousand Oaks, which is located about 40 miles west of Los Angeles, says his city is considered to be one of the safest in the country. That was echoed by one of the witnesses to the shooting. Borderline Bar and Grill was hosting College Country Night, which is popular with students, when the shooting happened.