Japanese authorities have found two Vietnamese workers dead at the demolition site for an apartment building in Tokyo, reported the local media.
According to Asahi newspaper, at about 8:30 of September 10, three men were reportedly fainted in a room on the second floor of a building that was being destructed in Setagaya ward of Tokyo.
Tokyo police said that among the three, all Vietnamese, two were dead and the third was taken to a hospital but remains unconscious and in a serious condition.
Carbon monoxide was detected at the site.
The Mainichi newspaper reported that the two workers apparently died of carbon monoxide poisoning.
However, there was no trace of anything having been burned at the site. A gas water heater in the room was not working as a hose was not connected to it.
It quoted sources close to the investigation as saying an electric generator was working in a room on the first floor. There is a possibility that carbon monoxide from its exhaust gas drifted to the second floor.
Currently, Tokyo police are coordinating with relevant agencies to investigate into the case.