Three workers died from suffocation shortly after they entered a huge water tank for cleaning.
The tragic incident happened yesterday at the Phapayom reservoir in Phapayom district of Phatthalung province.
According to police, four workers climbed down a 80-centimetres chamber of a huge six metres in diameter and three metres high water tank to clean it.
Within a few minutes after getting into the stifle tank in, three of them lost consciousness and one worker managed to climb up, calling for help.
Their colleagues later used a backhoe to open the lid of the water storage tank to enable smooth airflow and to rescue the three unconscious workers lying on the bottom of the empty tank.
They were then rushed to hospital but died on the way.
Police were looking for the foreman for questioning of the tragedy.
Source: Thai Public Broadcasting Service (Thai PBS)