It was Tuesday morning, in Uvalde, Texas, and Salvador Ramos was driving his truck to the local elementary school. A few hours later, 21 people had been murdered. It had been the second-most deadly school shooting in US history: 19 of the victims had been children aged between just nine and 11 years old, while the remaining two, teachers Eva Mireles and Irma Garcia, were gunned down protecting their classes.

But the tragedy hadn’t ended yet. The next day, not long after delivering flowers to the memorial for his wife, Joe Garcia fell down and died. And according to his family and friends, he was killed by a broken heart.

We know: “death from a broken heart” sounds impossible – like something medieval folk tales invented because they’d never heard of sepsis. But it technically is possible, Dr Philip Lee, a West London consultant physician in acute medicine and medicine for the elderly, told IFLScience.

“[It’s] a condition called takotsubo cardiomyopathy, where a sudden shock or grief causes heart failure and you die from that,” he explained. “Basically, too much noradrenaline [or] adrenaline, and the bottom of your heart stops pumping properly.”

Takotsubo cardiomyopathy is extremely rare, and usually affects older women. But there are plenty of examples of it happening: in 2011, for example, in the four days following a massive earthquake that killed 185 people in Christchurch, New Zealand, nearly two dozen people were admitted to hospital with the syndrome.

Joe Garcia’s death was “a classic case of broken heart syndrome from what’s been described,” according to Dr Deepak Bhatt, a cardiologist at Brigham and Women’s Hospital in Boston. But it’s impossible to know for sure before an autopsy, he told NBC News, as the symptoms and presentation of takotsubo are near-indistinguishable from a regular heart attack.

“Either type of heart attack can be triggered by extreme emotional stress,” he explained. “[The] sort that would happen if someone just heard, for example, that their wife had died.”

In fact, the only way to tell the two conditions apart is by inspecting the heart itself – which is actually how takotsubo got its name. In a “broken heart” attack, the left ventricle fills with a rush of blood and balloons out, so that it “looks like a fishing pot for octopus from Japan,” Lee told IFLScience.

“Tako = octopus,” he explained. “Tsubo = pot.”

The good news is that, much like a standard heart attack, takotsubo is rarely fatal, with more than nine out of 10 sufferers surviving the (already extremely rare) condition. Most patients – around four in five – recover without complications within a month or so, and it’s unlikely that an attack will reoccur.

For Joe Garcia, though – like so many before him – the trauma of his long-term love’s death may have just been too much for his heart to handle. Even worse, he may not be the last casualty of the Uvalde tragedy: multiple studies have shown a wide range of health impacts from the loss of a loved one that can prove fatal well after takotsubo would normally strike.

“In some cases, [takotsubo] might be a day later. It might be when someone realizes: ‘Oh, wow, my loved one actually is dead. They’re really not coming back,’” Bhatt told NBC.

“It sounds like that’s what happened” in this case, he said.