Authorities are still piecing together what transpired last night in the Borderline Bar & Grill in Thousand Oaks, Calif., where a gunman killed 12 people and then took his own life. The lack of answers leaves restaurateurs wondering: Why? Why did the shooter choose that place, and what triggered the rampage?

The answers may not be known for days, if at all. In the meantime, here’s what’s known about the establishment, as pieced together from social media, reviews and press coverage prior to last night’s catastrophe.

The Borderline was more of a dance hall than a true restaurant, known for playing live and recorded country music to which a largely college-aged crowd could line dance. The establishment provides an instructor-leader to help customers learn and follow the steps, like an aerobics instructor. The interior resembles a honky-tonk, with a 2,500-square-foot dance floor abutting a bar.

The place was popular with students from a slew of nearby colleges, including Pepperdine University, California Lutheran University, Moorpark College and California State University Channel Islands. At least seven institutions of higher learning are located within a 20-mile radius of the establishment.

The Borderline played to that audience every Wednesday with College Country Nights, when youngsters ages 18 to 21 are granted access despite being under the legal drinking age. The event runs from 9 p.m. to 2 a.m.

The 25-year-old establishment was known as a safe place for young people, a reflection of its sleepy, family-oriented suburban surroundings about 40 miles west of Los Angeles.

The gunman was identified midmorning as Ian Long. The only detail about him released by police was that he was 28 years old.

Early media and law enforcement reports say Long, dressed in black and wearing a flowing trench coat, entered the place at about 11:20 and lobbed a smoke grenade toward the bar. He shot the employee who was manning the door, and then opened fire on dancers with a .45-caliber handgun. About 30 shots were fired in total, according to the reports.

Customers broke windows to escape. Others hid in bathrooms. One survivor said she held a stranger's hand as they both listened to the rampage unfold outside their hiding spot.

Because of a quick heads-up from social media, news reports and noise from the commotion, some parents and relatives of the Borderline’s patrons arrived on the scene as survivors were still exiting the building.

Authorities and witnesses say the gunman was still firing when the police arrived. Among the victims was Ventura County Sheriff’s Sgt. Ron Helus, a 29-year veteran who was reportedly about to retire. Helus charged into the facility amid gunfire, according to witnesses.

In an ironic twist, a number of patrons inside the Borderline had also reportedly attended the country-music concert in October 2017 in Las Vegas where a gunman opened fire on the crowd from his room in a nearby high-rise hotel. Fifty-eight people were killed in that tragedy, the largest mass shooting in U.S. history.

Victims of last night’s shooting have not yet been identified. The colleges nearby have asked students to report any missing schoolmates as a way of determining who may have been killed.

More details will be reported as the story unfolds.

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