CURNO, Italy — When the call came at 11 p.m. on a Wednesday, Iris Limonta was shocked: Without any warning, she was told her 89-year-old mother had died.

“They told me, ‘We are sorry to give you bad news, but your mother is no longer with us,’” she said. “I asked them why they didn’t tell us before, so we could’ve spent the last few minutes with her.”

Teresa Maria Ambrosini had been living in the Casa Serena nursing home for nearly a year and a half and was in good spirits the last time Limonta spoke to her. But here, in the northern region of Lombardy, the epicenter of Italy’s COVID-19 outbreak, death comes quickly and without warning for family members.

That’s because the staff at Casa Serena were prohibited from allowing Limonta or any other family members into their premises. Since the outbreak began in late February, 65 out of their 200 mostly elderly residents have passed away — a third of their population gone in a matter of weeks.

Only a handful of these were confirmed cases of COVID-19. Most, like Ambrosini, who only displayed mild symptoms, were never tested before they died.

As of Tuesday, Italy’s official death toll stood at 21,067, the highest in Europe and topped only by the U.S. globally. But unofficial figures could be much higher. Interviews with medical professionals, funeral providers, and family members across Lombardy province suggest that vast numbers are dying at home or in nursing homes. This means they aren’t being counted in Italy’s official coronavirus death toll.

One recent study by the L’Eco di Bergamo newspaper suggests that in Italy’s worst-hit province of Bergamo, the real death toll could be more than double the official tally.

This is largely due to the fact that only those who are taken to the hospital for critical care are tested for COVID-19, while thousands of others who stay at home or in nursing homes for fear of overwhelming hospitals are never tested for the disease — even after death.

“Essentially, what we do is only test patients who come to hospital,” said Dr. Lorenzo Graziolo, a resuscitating anesthesiologist at Papa Giovanni XXIII hospital in the town of Bergamo. “If you’re at home, nobody comes to you to test you, so it might be that the actual number is very big.”

The ambiguity around her mother’s death is hard for Limonta to handle. What’s worse, the nationwide lockdown means that she and her family can’t give the family’s matriarch the farewell they wanted. Funerals, like any form of gathering, are currently banned in Italy. Instead, just a small handful of family attended a short prayer service at the cemetery. They watched as pallbearers in face masks and a cemetery worker in a full hazmat suit closed Teresa’s vault.

“It’s not like a regular funeral, where you can be with the body for two or three days,” she said. “It doesn’t seem real, honestly. It doesn’t seem real.”