The injured family members are being treated at Ninh Thuan Provincial General Hospital.
The Ca Na Commune People's Committee announced on Monday that the tragic incident occurred at 10.30 pm on October 8 when Lam Van Hoa, 35, set fire to his home using petrol. There were six family members inside at that time.
Hearing screams from the house, neighbours rushed in and tried to open the gate to rescue the family. Firefighters also arrived and controlled the fire at 11.30 pm.
However, Hoa's one-month-old baby boy had died and three other people including his mother-in-law, his wife and their three-year-old daughter were badly injured. Hoa then killed himself with a knife.
Initial investigation showed that Hoa set fire to his house after a quarrel with his wife.
Police are further investigating the case.
