A deeply indebted man is being treated in hospital after killing his wife, 25, and two young children, then slashing his own throat at his car audio shop in Klong Sam Wa district on Thursday night.
A neighbour called police to the small, one-storey NC Auto Sound premises off Hathai Rat Road in Bang Chan subdistrict about 7.30pm.
In the bedroom they found the body of Kingkaeo Pongpairote, 25, holding her dead 15-month old daughter and a 5- year-old girl lying dead nearby.
All three had their throats cut. There was drying blood on the walls and pooled on floor.
The husband, Natthasak Khamkhern, 46, was also in the room. He also had a large slash wound across his throat, but was alive, gasping for breath.
He was rushed to hospital. A 30-centimetre-long blood-stained knife was found at the scene.
Teerapol Detchang, 37, who has an auto garage nearby, said a friend of Mr Natthasak had phoned, asking that he urgently check out the car audio shop.
The friend said Mr Natthasak has complained about the burden of having to repay 8,000 baht a day on a debt with a loan shark.
Mr Teerapol rushed to the shop and discovered the bodies and the injured Mr Natthasak.
Police said surveillance camera footage showed a man arrived at the shop in a black pickup truck on Thursday evening.
Neighbours said the man came every evening to collect payment, but the shop was closed on Thursday.