A five-meter-high boiler exploded at a dyeing plant in Samut Prakan's Muang district early yesterday, injuring some 22 workers and residents. Several nearby homes were also damaged.
Most of the victims - 17 - were migrants, including a Myanmar man in charge of running the boiler. Four others were from a Thai family living next door to the factory.
The entire plant and its machinery, owned by Wongwisit Dyeing Co, was destroyed. Damage was estimated at about Bt10 million.
The site has been declared off-limits pending an inspection by police to determine the cause of the accident. No one has been charged yet.
The explosion blew out the upper and lower lids of the three-metre-wide boiler and sent the main unit flying some distance away from its original site. The explosion levelled six homes and damaged a few others while setting fire to machinery on the other side of the building. The blaze was extinguished in 30 minutes.
Police said six workers were on duty, including the operator, identified as Sor Mon San, 25, who was taken to the intensive care unit of a hospital with burns all over his body from scalding water.
A police source said there may have been problems with water pipes cooling the boiler, causing steam pressure to build up and exceed the safe limit and explode.
Thawee Kaewchart said the blast before 5.30am sent him and two children diving into a ditch by their house, which was flattened by the force of the blast. Thawee had burns on his arm and both of his children had burns on a large part of their bodies.
Jeerasak Sukhonthachart, permanent secretary of the Labour Ministry, said registered migrant workers would be provided assistance from the Social Security scheme while those unregistered would get initial assistance from their employer.
He said he would inspect the factory then visit those receiving treatment at Samut Prakan Hospital.