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.
- Tribute from 'devastated' firm after workers die at SSI site
- Huge boa constrictor is on the loose near Sydney after its shed skin is found on a construction site - and if you see it, you MUST stay away
- Lookout not in place when railway workers died, report finds
- A Construction Worker Dies Every 2.5 Days in Texas
- Understand the Perils of Working in a Construction Site
- Construction Site Accidents and Injuries
- Who Is Most at Risk for Construction Site Accidents?
- Construction sites: types and specific peculiarities
- 4 Benefits of Professional Debris Hauling At Construction Sites
- Man falls two storeys during argument on construction site