A foreign worker dies mysteriously at home... Colleague in the same room also taken to hospital = South Korea

Police have launched an investigation after an accident occurred at a villa in Pyeongtaek, Gyeonggi Province, leaving two foreign workers in their 20s dead and injured.
According to fire officials on the 17th, a call was made at around 7:12 pm on the 16th about a foreign worker complaining of stomach pain on the fourth floor of a four-story villa in Pyeongtaek, Gyeonggi-do.
Firefighters who responded to the scene found Mr. A, an Indonesian in his 20s, in cardiac arrest and transported him to a nearby hospital, where he later died.
B, an Indonesian colleague in his 20s who was in the same room as A, was found unconscious and taken to the hospital.
B's life is not in danger. C, a colleague who lives in the same room, reportedly found the two collapsed when he returned home from an outing.
Mr. A had gone to the hospital that morning with his colleague Mr. C, suffering from symptoms such as stomach pain, vomiting, and headache.
It was confirmed that this was not a gas leak. Fire department officials measured the carbon monoxide concentration at the scene and found it to be 40 ppm, below the allowable limit of 50 ppm.
The police will ask the National Forensic Service to perform an autopsy on the body of the deceased, and will also work with the Gas Safety Corporation and others to conduct detailed forensic analysis.