Supachai Saenyutitham, chief of the Nakhon Pathom Disaster Prevention and Mitigation Office, said the explosion occurred at about 10am at a switching board making factory, TIC Modular Systems in tambon Rai Khing in Samaphan district.
He said Chan Klinkaew, 40, Amnuay Suwandee, 57, and Surachai Jairaksa, 53, were severely injured.
The three were outside workers hired by the factory to clean air-conditioners. After they removed a compressor for cleaning, an explosion occurred when they used a gas we