A 28-year-old man shot and killed 12 nightclub patrons, staff and a police officer, and injured of at least 18 during a mass shooting at a bar in southern California early this morning.

Wednesday was college night at the Thousand Oaks club, with patrons as young as 18 allowed to enter, according to the Borderline Bar & Grill website.

Ventura county Sheriff Geoff Dean identified the shooter as Ian David Long, a  28-year-old former member of the U.S. Marine Corps. Long was reportedly suffering from PTSD and committed suicide following his rampage.

The bar was a popular hangout for students of the nearby universities.

“It’s not what you’d consider a wild night club,” Dean said during an interview on CBS This Morning. “It’s a pretty comfortable venue for young people to come and dance and to enjoy themselves.”

Long shot and killed Ventura County Sheriff Sgt. Ron Helus as the officer was trying to enter the club. He then reportedly committed suicide.

“It’s very personal that someone I worked with for 29 years was also a victim,” Dean said.

According to tweets posted by Pepperdine University, located a few hours away, students from its campus were at the bar. And the Thousand Oaks college, Cal Lutheran University, canceled classes on Thursday while welcoming its community to Samuelson Chapel to grieve and support each other.

Former Thousand Oaks residents shared their grief and outrage online.

“I worked in Thousand Oaks,” wrote SF State alumna Shahni Ben-Haim on Facebook. “I went to school in Thousand Oaks, I used to perform at the bar, I used to go to that bar with friends. You would never believe this would happen in Thousand Oaks America.

“We have needed gun control! It’s not enough to say NOW! We have to move forward and fight for justice and gun control.”

At SF State, students said although they have concerns, news of mass shootings have become commonplace.

“I feel like it’s just another day,” said sociology student Sonia C., who didn’t want to provide her full name.

Other students said they didn’t hold out much faith that gun control measures would be successful.

“It’s just not surprising that not much reform would come out of it,” said Rasha Kunna, an SF state pre-nursing major.

She added that she was unaware of the active threat training videos available through the SF State University Police.

“They should let more people know that they have it,” Kunna said.