SEOUL - When a patient died of the Middle East Respiratory Syndrome (Mers) in front of her eyes during an outbreak in 2015, nurse Kim Hyun-ah wrote that she would "cling on to every patient and never let go, so the angel of death cannot take them away".
Her letter, published in a major newspaper on June 15, 2015, moved many to tears.
In March, three years after she had quit to become a writer, Ms Kim returned to the front line when Covid-19 broke out in the south-eastern city of Daegu, where her mother lived.
It was a time of chaos when the city was running short of medical staff and supplies as the number of patients skyrocketed.
South Korea was then the second-most infected country after China, and reported daily new cases got to as many as 909 in an outbreak linked to a local church.
"The situation in Daegu was really urgent and I felt very uncomfortable seeing the news," Ms Kim, 46, who lives in the Gyeonggi province surrounding Seoul, told The Straits Times.
"Junior nurses were working in the ICU (intensive care unit) and they didn't know how to handle the patients. If I went to help, they could take a break and prepare for the long fight ahead."
There was only one obstacle - objection from her 70-year-old mother, who did not want her daughter to risk her life again.
"I promised her that I would not get infected, and I told her that I may regret it for the rest of my life if I didn't go to Daegu," said Ms Kim, who has 21 years of experience working in the ICU. "People there need me, I have to go."
Ms Kim, who is single, spent a month working the night shift as a volunteer in the ICU at Keimyung University Dongsan Medical Centre, one of the first medical facilities in Daegu to focus on treating coronavirus patients.
By the end of March, South Korea had brought the outbreak under control with mass testing using innovations such as drive-through testing, and aggressive contact tracing.
The number of daily infections fell below 100, and the country was widely hailed as a role model for successfully curbing the outbreak without resorting to extreme measures such as a lockdown.
Now fighting a new wave of infections, South Korea has reported 23,455 cases of the virus as of Sept 25. The death rate has reached 395.
Ms Kim praised the government's efforts in fighting the pandemic, saying that it "did very well" compared with during the Mers outbreak.
First detected in the Middle East in 2012, Mers spread to South Korea in May 2015 through a businessman flying home from Dubai. The virus spread largely within hospitals over the next two months, killing 20 per cent of 186 patients.
Globally, the fatality rate was 34 per cent of 2,519 cases reported to the World Health Organisation till Jan 31 this year.
The authorities fumbled as they had no experience battling an infectious disease, and new cases were shrouded in secrecy, triggering mass panic.
The 58-year-old woman who died in her care was the 25th patient and first Mers fatality in South Korea.
"She was so lonely in the ICU and after she died, we covered her with a white cloth and waited until government officials came to collect her body for cremation. No one could see or touch her."
Her death shook Ms Kim so much that she started to keep a diary of her feelings, which culminated in the letter to JoongAng Ilbo newspaper.
With coronavirus, however, family members have at least been able to view the bodies of their loved ones, according to Ms Kim.
She recalled the death of a 46-year-old man who had caught the virus from his older brother, a worker in a small hospital.
"I was in the ICU when he died at 4am. We disinfected his body, shaved his face and brushed his teeth, then put him in a zipper bag that had a small transparent segment showing his face," she said.
"When his family came, we suited them up and gave them a few minutes to say goodbye. They were crying and screaming, but they got to see him one last time, which was the least we could do for them."
Work was tough, and she said nurses faced a higher risk of infection, as they stayed in the ward with patients throughout their shifts, unlike doctors, who came three times a day.
"One nurse took off her mask, as she couldn't breathe well, and next thing we knew, she had caught the virus," said Ms Kim.
"I wore a hazmat suit 42 times. Taking it off is dangerous because the surface could be covered with the virus, so I always had to do it carefully."
But she was motivated by fellow nurses and members of the public who left messages of encouragement. The rapport and moral support was very strong, she said.
Ms Kim has since returned to life before Covid-19, spending her days writing the script for a drama serial based on her personal experience working as a nurse in the ICU. Filming is slated to start later this year, or early next year.
But she is prepared to volunteer again if a major outbreak emerges.
"Fighting the coronavirus is like fighting a war," she said.
"A nurse is like a soldier. The more soldiers we can gather, the higher our chances of winning. A soldier must go to war, so must I."