SEOUL -- The Sindorim neighborhood on Seoul's southeastern edge is a crossroads of commerce and transport, home to factories and office buildings. Sindorim Station is a transfer point onto the Seoul metro's busiest line, and a vital gateway to the capital from the nearby city of Incheon and surrounding Gyeonggi Province.
So the discovery of at least 99 confirmed COVID-19 infections linked to the district this week has deepened fears that the virus could spread, via commuters, from Sindorim throughout the crowded capital area -- home to much of South Korea's population of 52 million.
The cluster of coronavirus cases was discovered at an insurance company call center, housed in a high-rise building a short walk from Sindorim Station. The building is shared with other businesses.
Local media reported that the company in question employed temporary workers that regularly left the office to meet with customers. Public health officials are now scrambling to contain the Sindorim outbreak and track down anyone who could have come into contact with a virus carrier.
"The building was immediately closed and Seoul city started disinfecting," a member of the municipality's media relations team told the Nikkei Asian Review in a text message. "The 207 employees at the call center who worked on the 11th floor and their entire families have been tested. All 550 employees on the 7th, 8th and 9th floors are also being investigated."
An ad-hoc government-run diagnostic center has also been opened outside the building, part of a massive nationwide testing campaign.
"Going forward, the fact is that there could be cluster infections at any time, in any neighborhood in any part of the country. So we're working to seek out cases of the virus, down to the very last person," Kwon Jun-wook of the Korea Center for Disease Control said on Tuesday.
The infection cluster in the capital came after South Korea had reported declines in the number of new infections for several days. Eighty-two percent of South Korea's COVID-19 infections are concentrated in the southern city of Daegu and its surrounding area. There, a large portion of cases were tied to Shincheonji, an obscure religious sect accused of spreading the virus through its worship services.
Residents of Seoul, while taking measures to reduce their risk of contracting the virus, had felt safer than their counterparts in Daegu until this week. But the Sindorim cluster has pushed up the level of anxiety in the capital.
"As a healthy adult, I'm not that concerned for myself as I could probably overcome it easily, but very cautious and worried due to the baby, for sure," said Yoon Ji-young, a 34-year-old white-collar worker in southern Seoul and mother of a 1-year-old boy.
To limit her risk of infection, Yoon has been working from home. To protect her son, she and her husband are "keeping away from crowds. Basically staying home every day, except for taking [the boy] to the small mountain behind our house."
Even before the Sindorim cluster, daily life in the capital and throughout the country was replete with reminders of the outbreak.
The central government has been encouraging companies to take precautions: allowing workers to telecommute, distributing hand sanitizer, ensuring workplaces are well-ventilated and checking employees for fever upon arrival.
Every day, millions of smartphones rattle in unison with admonitions from public health authorities to take preventive steps, such as disinfecting hands and wearing face masks. Local governments also send out such alerts when a COVID-19 case is confirmed, urging people to avoid the area the carrier had recently been in.
Since the virus has been the main topic of conversation in the capital in recent weeks, not everyone was caught off guard by the news out of Sindorim.
"I knew it would eventually make its way up to Seoul. It was just a matter of time," said Lim Mo-ran, an office worker who lives in southern Seoul.
She said she wishes the government had more strictly managed incoming travelers from China, and come up with an efficient system of mask distribution. She feels like fears of the virus are fraying social life in the capital. "I don't know who has it or who doesn't, especially since symptoms aren't always noticeable," Lim said.
Lim has her two young sons wear masks at all times in public places, due to concerns over infection from passersby.
"It's sad because I feel as though I can't trust anyone."