A well-known leader in Canadian emergency medicine has died.

Dr. Paul Hannam, who was the chief of emergency medicine and the program medical director at North York General Hospital, died suddenly on Saturday. He was 50.

Hannam reportedly collapsed while out running, friend and fellow emergency physician Dr. Howard Ovens said in a tweet.

“Olympic sailor, marathon runner, family man, ED director at NYGH, a sweet, thoughtful, compassionate and gentle man died suddenly today on a run. The quintessential mensch. Hug someone you love,” he wrote.

North York General Hospital also shared the news in a tweet.

“Our hearts are heavy as we remember our dear friend and colleague,” they said, calling Hannam a “highly respected and trusted colleague, devoted to patients and community.”

Hannam was also well-known and well-liked in Toronto’s east end as he’d previously served two terms as the chief emergency director at East York’s Michael Garron Hospital.

“Our hearts are heavy as we remember our dear friend and colleague, Dr. Paul Hannam, who served as our Chief of ED for 10+ years. We will not soon forget his incredible contributions to our hospital and community," the hospital tweeted.

President and CEO Sarah Downey said Hannam was a “wonderful person in every way” who spent “many years caring for our communities.”

Mount Sinai’s Schwartz/Reisman Emergency Medicine Institute also tweeted about Hannam, who they called a “kind and thoughtful leader, family man, incredible athlete, wonderful friend and colleague.”

Several of his former colleagues and patients have since taken to social media to express their sadness and shock about this loss and share memories about Hannam, who aside from working at NYGH, was also an assistant professor at University of Toronto’s Department of Family and Community Medicine.

Hannam also held various medical leadership and hospital administration roles since 2006.

Funeral arrangements are unknown at this time.