A couple and their two-year-old daughter were found dead inside their rented room in Binh Thuan Ward, District 7 on Friday morning after a relative was unable to contact them at that time.
She later came to the house to call, but no one answered the door.
Through the door she saw some people lying on the floor. She called some local residents and they decided to break open the door and discovered that three people were dead already.
The victims were identified as Ha Cong Hung, 32, his 41-year-old wife and their two-year-old daughter. Hung worked as a security guard while his wife was a worker at some local firms.
A gas cooker was found operating with a boiling pot of corncob inside the 12-square-metre room which had all doors and windows closed.
They informed local authorities of the incident.
Initial investigations showed that the three victims might have died from asphyxiation due to CO2 inhalation coming from the gas cooker.
Police are further investigating the cause of the incident.
