A college professor in Argentina who had been suffering from persistent COVID-19 symptoms collapsed and died at her home while giving a lecture to a virtual class of students.

The Sun reported that Paola De Simone, 46, who was a professor of 20th-century world history at Universidad Argentina de la Empresa in Buenos Aries, complained that she was having trouble breathing while conducting a class over Zoom last week. This caused her students to panic as they told her to give them her home address so they could send help. De Simone simply gasped “I can’t” before collapsing.

De Simone’s husband, a doctor, found her body that evening when he got home from work. De Simone, who is also survived by a daughter, had previously opened up on Twitter about her health struggles and her husband’s work during the pandemic.

“It is very complicated. I have been here [with the virus] for more than four weeks and the symptoms do not go away,” De Simone wrote. “My husband is exhausted from working so much at the moment.”

Ana Breccia, one of the students who was in the virtual class, described her professor’s final moments.

“She began by saying that she had pneumonia, we saw it was worse than in previous classes,” she said. “At one point she could not continue passing slides, nor speak and she became unbalanced.”

Another student described De Simone as an “unforgettable teacher, one of those who give you a hand in everything, who make you love what you study, who go out of their way for their students. We are going to miss you a lot.”

Silvina Sterin Pensel, an Argentine journalist in New York, said that she was not surprised to learn that her friend and former classmate had continued teaching.

“I totally portray Paola deciding, ‘I can totally do this, my students need me,’” she told the Washington Post, adding that De Simone’s death is a “sad reminder that the virus is real.”

“The virus is still making rounds in Buenos Aires,” Sterin Pensel explained. “In Argentina, the confinement has been very strict, so people are showing signs of fatigue in complying. But these kinds of reminders, these awful reminders, they shake your core.”

The Universidad Argentina de la Empresa released a statement saying that the professor’s death had left the institution with “deep pain.”

“Paola was a passionate and dedicated teacher, and a great person, with more [than] fifteen years of experience,” the school said.