(CNN) -- It all seemed like a Friday night prank in the beachfront paradise of Isla Vista, the off-campus housing quarter for students from University of California at Santa Barbara and the local community college.
The pops sounded like firecrackers, a common mischief.
And the gun looked fake, like one used for pellet games.
But what seemed like a college joke at first became very real.
Sienna Schwartz saw the gunman driving by her and thought he was a hoaxster -- until she felt the whoosh of a bullet passing her skin.
"He lifted up a little black pistol and ... I just thought it was an Airsoft gun or something, so I was like, hey, what up?" she said, becoming tearful as she recounted the experience.
"And I turned around and I started walking the other way," she said. "He shot ... I just felt the wind pass right by my face."
Schwartz broke down in retelling how the beauty of Isla Vista became a scene of mass death Friday night.
In all, seven people were killed, including the gunman who fired into crowds while driving his black BMW.
It was the second time that a mass killing has occurred in the unincorporated community in 13 years; the other one also involved a motorist.
Friday night's violence couldn't have picked a more beautiful college setting.
UCSB is renowned as a school on the beach, and as such, it's one of the most scenic campuses in America, caressed by cool Pacific breezes.
Just 100 miles from Los Angeles, Santa Barbara attracts weekend crowds seeking a getaway. Its main street features boutiques and eateries in stylish Spanish-mission architecture.
Isla Vista is the adjacent residential quarter for students mostly enrolled in UCSB and others at Santa Barbara City College. The community sits on beachfront bluffs just west of UCSB and offers off-campus apartments where students commonly double up in one bedroom.
In fact, Isla Vista holds legend status as the most densely populated square mile in California, though the county says its size is actually a half-square mile, or 320 acres.
Officially, Isla Vista is an unincorporated community of 20,000 people -- 13,000 of them are students -- in Santa Barbara County, the county says.
The streets prove the student presence: they're lined with bicycles.
Friday night's mass shooting occurred on an weekend evening when Isla Vista is typically jammed with students moving shoulder-to-shoulder from one party to another.
On Saturday morning, however, the community was a massive crime scene.
Pizzerias, delis, cafes and convenience stores downtown were lined with yellow police tapes zigzagging everywhere -- because the drive-by gunman apparently fired upon several places while in motion.
Bullet casings lay scattered on the street, and storefront windows were shattered.
2001 mass killing
As grisly as it was, the setting wasn't the first time that Isla Vista has known a mass killing, especially by a motorist.
In 2001, David Attias, son of film director Daniel Attias, ran over five people in Isla Vista, killing four of them, and exclaimed he was the "angel of death."
Attias was convicted of four murders in 2002, but a jury later ruled him not guilty by reason of insanity. Attias was then sent to a California mental hospital.
In Friday night's deaths, witnesses -- largely of college-student age -- initially thought the unfolding events were student antics.
Sounded like fireworks
Summer Young said she was walking down the street and heard what sounded like fireworks set off by students. "People get stupid out here sometimes," she said.
But the pops were gunfire, and the car passed her, she learned.
"He was just firing up shots," Young said.
Another witness, Cayla Bergman, a UCSB student, also described the bangs as fireworks. "We're used to loud noises around here," she said.
But then the crowds went into a panic.
"A bunch of people from outside just started running into the store," Bergman said.
Kyle Sullivan, 19, a student at Santa Barbara City College, came upon three young women -- all shot -- on a lawn in front of the Alpha Phi sorority, located in a cluster of Greek houses in Isla Vista.
One woman appeared to be dead. Another was struggling and "just barely able to move her eyes." A third, wounded in the kidney and arm, was on the phone with her mother, telling her she probably wasn't going to make it and "how much she loved her," Sullivan said.
"It was a huge shock last night," Sullivan told CNN in an interview on the sorority lawn, reconstructing events. "I really wasn't able to sleep at all. It was heartbreaking, that something would happen in our community like this."
Nikolaus Becker, a graduating high school senior who was visiting Isla Vista, was eating a burger in a restaurant when he and friends heard pops, thinking they were fireworks. Other students were doing homework inside the eatery.
"We were actually joking around about it," he said of the popping. "People were riding their bikes around outside, and parties were still going on."
Then Becker and friends heard two more sets of bangs -- with police running. They also saw a speeding car -- moving at 50 mph, screeching around a corner.
"Nobody knew what was going on, and everybody was kind of scared to go outside," Becker said.
When he finally went outside a half hour later, Becker saw body bags on the street.
Both colleges expressed sympathies Saturday. They are now coordinating counseling and student support services.
"Our hearts are aching as we learn about the tragedy that unfolded in Isla Vista last night," a Santa Barbara City College statement said Saturday. "We know our students co-mingle with UCSB students and Isla Vista residents as part of our greater community and we all, as an extended family, are impacted by this unimaginable event."
UCSB is providing temporary housing for displaced students.
"Our campus community is shocked and saddened by the events that occurred last night in the nearby community of Isla Vista," a university statement said.
CNN's Paul Vercammen contributed to this report.