More than a month after interns and residents left hospitals in protest against the government's expansion of medical school enrollment quota, a university hospital professor who kept working at the hospital, has died, shocking the medical community.

Pusan National University Hospital (PNUH) said a professor named "A," who worked in the Ophthalmology Department, died on Sunday.

According to the medical community, Professor A arrived at the emergency room of a tertiary general hospital in Busan at midnight Sunday. The hospital performed cardiopulmonary resuscitation (CPR) for an hour but failed to save him.

The deceased professor was reportedly suffering from overwork, getting little sleep as the emergency room work increased in the aftermath of the recent resignation of medical residents and other reasons. It was also reported that the ophthalmology department was seriously “groggy,” and professors were under extreme pressure.

The medical community has expressed its condolences.

PNUH said that it is difficult to know now other than that Professor A has died.

"At this point, we don't know anything, but that Professor A has died, an official from PNUH said in a phone interview with Korea Biomedical Review on Sunday, adding that the cause of death and other things could not be confirmed.

Meanwhile, professors who remain at the hospital and continue treating patients complain that they have reached their “limit.” As previously announced, the mass of resignations of medical professors were to begin on Monday.

The Medical Professors Association of Korea (MPAK), which comprises professors from 39 medical schools across the country, decided to implement “optimal care” after the professors submitted their resignations individually on Monday.

From Monday, outpatient, surgical, and hospitalization care will be limited to 52 hours a week, and from April 1, outpatient care will be minimized to ensure stable care for severe and emergency patients.

Another faculty organization, the Emergency Committee of the National Association of Medical Professors, also said that it actively supports the working conditions set by MPAK and resolved to submit its resignation letters on Monday.

Meanwhile, the MPAK met with Han Dong-hoon, temporary chairman of the ruling People Power Party, on Sunday and requested mediation between the government and the medical community on medical issues, including the resignation of medical residents and the class boycott by medical students.

The association will release the meeting contents through a briefing later on Monday.