The late James W. Rouse’s vision for Columbia was for a safe, open community devoid of the racial, social and economic problems that plagued so many other places. The Mall in Columbia has for decades been at the heart of that community — its downtown.

On Saturday morning, as people filled the mall — to shop, to eat, to get out of the cold — their gathering place became a crime scene when a man with a shotgun killed a man and a woman before shooting himself.

“The mall has traditionally been Columbia’s downtown,” said Howard County Councilwoman Mary Kay Sigaty (West Columbia), who lives less than a mile from the shopping center and often meets friends there to walk. “Our mall is central to many lives in Columbia.”

Added Phillip Nelson, president of the Columbia Association: “It’s a gathering point.”

Columbia, one of the nation’s first planned communities — where people could live, work, play and be entertained — first housed residents in 1967. The mall opened just four years later.

Violence erupted at a suburban mall in Columbia, Md. on Saturday morning, after a shooter emerged from among weekend shoppers. Police confirmed that three people were left dead, including one believed to be the shooter.

In the mornings, there are moms with strollers stretching their legs as they walk their young children around the mall. Columbia’s older residents sip coffee at Starbucks or Panera, where they are likely to run into a few county police officers grabbing caffeine before their shifts. The mall also is a place for teenagers to socialize; many of them get their first job folding clothes at one of its many shops or waiting tables at its restaurants.

The mall is simply part of the daily routine.

That’s by design. Rouse started what became Columbia, about 25 miles northeast of Washington, with 14,000 acres of farmland, much of it a former dairy farm, then designed and built a series of villages. Each had its own small shopping area. But there was no central downtown, no Main Street where everyone would gather, so the mall became that spot.

Calvin Anshen, 70, goes there every Friday to see a movie. On Saturday, his wife was headed to the mall with her 94-year-old mother to do some shopping at Nordstrom just after the shooting happened. When they arrived, they were startled to see people running into the parking lot.

Sigaty said the mall is bustling on Saturdays. Shoppers from around the region would join the Columbians. Children would line up for rides on the merry-go-round, located on the mall’s second floor, where the shooting happened. Teenagers would grab pizza slices at Sbarro near the Sears. With more than 200 stores, as well as movie theaters and several restaurants, the mall has long been one of the region’s more upscale attractions.

“Every time you go to the mall, you’re going to run into someone you know,” said Allison Klein, a former Washington Post reporter who grew up in Columbia and wrote about her home town in a 2005 Post article. “It’s just that kind of place.”

In the piece, Klein recalled Rouse’s utopian vision.

“Rouse made sure that fences separating houses were frowned upon, if allowed at all, and that homes did not have mailboxes,” she wrote. “Instead, in an effort to foster neighborly conversation, a community mailbox was installed at the top of each street. He took the idea a step further by establishing the Columbia Association, which allowed a family to pay one fee, no matter how many children, for membership at all of the city’s gyms, tennis courts and swimming pools.”

The community motto is “Choose Civility.”

Nelson, the Columbia Association president, said people in Columbia have strong ties to their community.

“There are 100,000 people here, but it still has that small-town atmosphere,” he said. “We like to think of ourselves as the Sea of Tranquility between the two Beltways.”

Last year, General Growth Properties, which owns the mall, broke ground on an addition that will add 70,000 square feet to the property. County officials have approved plans to remake Columbia in hopes of bringing more of a traditional downtown feel, adding apartment buildings and street-level retail stores that can attract young people who might otherwise choose to live in Silver Spring or the District.

But unlike other D.C. area communities that have started that transformation by bulldozing the local mall, leaders have said Columbia’s would not suffer the same fate. Instead, it will continue to play a central role in community life.

Just over half of Columbia residents are white, a quarter are black, 11 percent are Asian and about 8 percent are Hispanic or Latino. About 18 percent of residents were born in another country. The median income from 2008 to 2012 was $98,529, and the median home price was $371,200.

“In reality, you don’t see this kind of community anywhere else,” said Anshen, the moviegoer who moved to Columbia in 1975 and raised three children in a home just five minutes from the mall. “People are friendly and open — they don’t put on airs. It’s a laid-back community of people who are here for the same reason — to have a quality life.”

Ellen Kim, a manager at the Lucaya clothing store two doors down from Zumiez, where the shooting occurred, was among the many people shocked that something like this could happen in her community.

“Columbia Mall is such a nice, quiet mall,” she said.

Added Sigaty: “This is the kind of thing that really shatters your peace and your sense of security.”

Emma Brown contributed to this report.