A gunman shot and killed 12 people before turning the gun on himself at a bar hosting a college night in Thousand Oaks late Wednesday.

Ian David Long, 28, was alleged to have entered Borderline Bar & Grill at 99 Rolling Oaks Drive shortly after 11 p.m. when it was packed with students from nearby colleges attending a weekly College Country Night. He shot a security guard and bar staff members before opening fire on the patrons, according to Ventura County Sheriff Geoff Dean, the Associated Press reported.

Sheriff’s Sgt. Ron Helus entered the bar not long afterward with a California Highway Patrol officer and was shot by Long. Helus died at a hospital early Thursday morning, Dean said, according to the Los Angeles Times.

Moorpark College, where some of the students at Borderline attend school, will remain open on Thursday. California Lutheran University cancelled all classes. Both schools are making counselling resources available to students.

At least five California State University – Channel Islands students were at the bar and all returned to campus safely, President Erika Beck wrote in a letter posted at the school’s website.

The shooting has caused disruptions of some planned events, including the cancellation Cal Lutheran’s Corporate Leaders Breakfast scheduled for Friday morning in Woodland Hills and the Thursday night grand opening of the California Museum of Art Thousand Oaks at the Oaks Shopping Center.

Jill Lederer, chief executive of the Greater Conejo Valley Chamber of Commerce, told the Business Journal that while Borderline was not a chamber member, the group did work with the bar on the OakHeart Country Music Festival that has taken place for seven years every summer. The bar has “an excellent reputation,” she added.

At this point, Lederer did not think anyone was even considering any business implications from the shooting.

“Everybody is completely focused on the victims right now,” Lederer said. “(Chamber members) know we have excellent law enforcement, and this is such a safe city, and this was a really tragic and isolated event for our community.”

Long is a Marine veteran who served in a combat tour in Afghanistan from November 2010 to June 2011.

The Ventura County Community Foundation has set up a fund for those who want to make a donation to the families affected by the shooting: https://vccf.org/donate/make-a-donation/.

The Rotary Club of Westlake Village also has set up a GoFundMe page for the survivors. Borderline owner Brian Hynes is a member of the club.