An influential doctor who spent decades studying and treating lung conditions has died of acute respiratory distress syndrome, or ARDS, caused by COVID-19,University of California, San Francisco doctors say.

John F. Murray, a UCSF Emeritus Professor of Medicine, died at the age of 93 in Paris on March 24, according to an emailed announcement to department of medicine staff.

Murray was a key figure in defining, understanding and treating ARDS. "Sadly and ironically," he died of respiratory failure caused by that condition, the email signed by seven doctors says.

ARDS is a common killer among critically ill patients hospitalized with COVID-19. The new virus often targets the lungs and can cause respiratory problems including bronchitis and pneumonia. In a small number of severe cases, ARDS develops.

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Murray was instrumental in redefining the medical community's approach to the treatment of lung diseases and helped lead a surge of new doctors to the field, Philip Hopewell told USA TODAY.

Hopewell, former chief of the Zuckerberg San Francisco General Hospital Pulmonary Division, said when Murray entered pulmonary medicine, the field was mostly focused on a single disease: tuberculosis.

Murray's work broadening the field and training others helped pave the way for the modern ICU, multiple colleagues told USA TODAY. His work is proving integral to the treatment of the current pandemic, Hopewell said.

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“He had a hand in almost every part of our field,” Courtney Broaddus told USA TODAY. Broaddus is editor-in-chief of a respiratory medicine textbook that bears Murray's name.

In addition to writing the influential book, "The Normal Lung," Murray was chief of pulmonary for more than two decades at San Francisco General Hospital. He was also a former president of The American Thoracic Society.

Murray was beloved for his bedside manner and respect for other health care professionals including nurses, Broaddus said. He was known for wearing a bow tie, partly out of consideration for patients – he didn't want his tie to drag over them as he attended.

Murray was a “sophisticated, worldly human being” who was living in an apartment in Paris with his wife, novelist Diane Johnson, at the time of his death, according to Morris Schambelan, who knew Murray for more than 50 years.

Among other accomplishments, Johnson is known for co-writing the screenplay for the classic Stanley Kubrick film "The Shining."

In addition to his wife, Murray is survived by two children, four stepchildren and 14 grandchildren.

Murray's age was among the factors that made him a high-risk patient for COVID-19, according to Hopewell.

“Coronavirus was new to him, just as it was to all of us,” Broaddus said.

Contributing: Adrianna Rodriguez, USA TODAY.