Fourteen San Franciscans have died of COVID-19 — officially. That’s the count from public health officials, but there could be more. And we may never know the real tally.

Residents of an Inner Richmond apartment building wonder whether their neighbor belongs in that grim tally.

Larry Kaplan, 70, was a longtime driver for Yellow Cab and made numerous airport runs during his shifts, picking up travelers arriving from all over the world.

In February, the fourth-floor resident developed a deep, loud, persistent cough that neighbors in other apartments heard for weeks. He complained to his neighbors that he couldn’t play his beloved clarinet because his lungs were so weak. He said he was exhausted and looked it, too, but he couldn’t afford to stop driving.

He said his doctor had diagnosed him with pneumonia, but he wasn’t happy with his medical care and wasn’t getting any better.

And then on March 19, Rob Geyer, a second-floor resident in the 10-unit building, heard his buzzer ring. It was the San Francisco police. They were there for a welfare check on Kaplan requested by a co-worker, but he wasn’t responding to his own buzzer. Geyer let the police inside, and they entered Kaplan’s apartment.

“They found him,” Geyer said. “They said he’d probably been dead for about a week.”

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Geyer said the police mentioned their concern that the coronavirus had struck down Kaplan. He lived alone except for his cat, which was taken to Animal Care and Control. His landlord had his belongings removed and hired a biohazard company to clean the unit. And Kaplan’s body remains at the medical examiner’s office, his cause of death still undetermined.

The office would say only this in an email: “Larry Kaplan, San Francisco resident, passed 03/19/2020. This case is still open. There is no other information I can give you at this moment.”

There is widespread speculation among doctors around the country that official death counts from COVID-19 are lower than the real number. There still aren’t nearly enough tests to determine who has the disease, and some people are dying of it without ever knowing they had it.

Dr. Allison Bond, an infectious disease fellow at UCSF, said there is “absolutely” concern that COVID-19 deaths have been undercounted, including here in San Francisco.

Testing has not been widespread enough to catch everybody, she said. Only recently have doctors understood that COVID-19 can be present with symptoms other than just a fever and cough, including gastrointestinal distress. Medical experts also just realized that people can have two infections at once — such as the regular flu and COVID-19 — so testing positive for one doesn’t rule out the presence of the other.

Asked whether she thinks San Francisco’s official death count is accurate, Bond said, “It’s exceedingly unlikely.”

Rachael Kagan, a spokeswoman for the San Francisco Department of Public Health, said local officials think “it’s unlikely that our death counts are inaccurately low.”

“We have been testing hospitalized patients from the beginning who have respiratory symptoms but no other known cause,” she said. “We have been aggressive in our testing of those most at risk.”

Dr. Grant Colfax, director of the Public Health Department, told a news conference that the medical examiner’s office is conducting postmortem coronavirus tests in accordance with guidelines from the Centers for Disease Control and Prevention, which call for testing of “people who died suddenly who have a known contact with somebody who’s been COVID-19-positive,” he said.

In fact, the first COVID-19 death tracked in San Francisco on March 24 came from a postmortem test at the medical examiner’s office of a man in his 40s with other health conditions.

But not everybody who dies is known to have had contact with someone with the coronavirus, and not everybody will wind up at the medical examiner’s office for postmortem testing.

Bill Barnes, a spokesman for the city administrator, said the vast majority of people who die in San Francisco will have their death certificate signed by a doctor who can attest to the cause of death. Their bodies will be taken directly to funeral homes. About 5,800 people die in San Francisco in a given year — and of those, roughly 1,300 will be taken to the medical examiner’s office.

Those are often people who, like Kaplan, lived alone and died unattended or people whose death is suspicious.

“The moral of the story is people should check on their neighbors,” Barnes said. “There are certainly people without support systems.”

Kaplan’s neighbors would like to know how he passed — both to understand whether they were in proximity to the virus and because they cared about the man who’d lived in the building since 1977 in that casual city kind of way.

“When we saw him on the street or in the lobby in the building, we would talk, but we didn’t hang out regularly or anything like that,” Geyer said. “He was pretty gregarious. He could talk for long periods of time — sometimes it was a little inconvenient even.”

Kaplan years ago had scored a once-coveted, expensive medallion, the permit allowing a taxi to operate, but complained to his neighbors it was nearly useless after the explosion of Lyft and Uber. He told them he could barely swing it on his Social Security checks and cab income.

The building’s landlord, Gaspare Indelicato of Gaspare’s Pizza in the Richmond District, said Kaplan was a “typical New Yorker — very friendly, but he kept to himself.”

Indelicato said he’s asked police repeatedly for his tenant’s cause of death, but hasn’t gotten an answer.

“We’re as curious as everybody else,” he said. “Thank God everybody’s safe in the building. Nobody’s sick that we know about.”

He said he told tenants that if they get sick and have trouble paying the rent, he’ll give them a reduction.

Kaplan’s nephew, Aaron Kaplan, a 51-year-old clinical psychologist in Oahu, Hawaii, said he knew his uncle hadn’t been feeling well and had been diagnosed with pneumonia, but had no idea how bad the symptoms had gotten and was shocked to learn he’d died.

“Looking back, he probably had COVID,” he said. “He was too young to die.”

Aaron Kaplan said his father and uncle grew up in Queens, and Larry Kaplan hitchhiked with a girlfriend to San Francisco in his early 20s. Larry and his girlfriend split up, but his love affair with San Francisco lasted a lifetime. He took his nephew to lots of concerts — he especially loved jazz — and they’d always end the night at the now-shuttered Shimo Sushi on Clement Street, talking late into the night with its owner.

Aaron Kaplan said his uncle was “a brilliant man” whose apartment was stuffed with vinyl records and “floor-to-ceiling books about philosophy, religion, spirituality and politics.”

“He was a voracious reader and studier of life. He could schmooze with anybody,” Aaron Kaplan said. “He was a real character, a New Yorker at heart.”

Eliote Durham, another neighbor of Kaplan’s, said the two bonded over music — she plays the trumpet, and he played the clarinet. They went to the Hardly Strictly Bluegrass festival together once, and he loved it.

Her mother, Carol Terrell, visited from Tennessee for several weeks in February and March and had a long chat with Kaplan on the staircase about his health problems.

“He said he couldn’t play the clarinet anymore because he didn’t have any wind for it, and his chest hurt. He felt bad, really too exhausted to drive the cab,” Terrell recalled. “He knew he had to get back to the doctor, but he said he didn’t feel like doing it that day. Maybe he’d go another day.”

She slipped a note under his door with recommendations for finding affordable health care, but she doesn’t know whether he received it. Her daughter phoned her when she was back home to tell her Kaplan’s body had been found.

“I was really sad that he died and that none of us knew it,” Durham said. “I didn’t know it for a week.”

Rest in peace, Mr. Kaplan.

San Francisco Chronicle columnist Heather Knight appears Sundays and Tuesdays. Email: hknight@sfchronicle.com Twitter: @hknightsf Instagram: @heatherknightsf