Witnesses said Suwat was supervising the construction of a two-storey luxury house, with Chen standing nearby, when the scaffolding fell down. More than 10 people were working at the site.
Rescuers from the Poh Teck Tung Foundation spent more than an hour removing scaffolding debris before they could bring out the bodies of the two victims.
Deputy Nonthaburi Governor Ampon Angkhapakornkul inspected the site and declared it off-limits, except to relevant officials. He also instructed the authorities to provide help to the victims in line with government procedures.