Three people died in Hanoi after inhaling toxic fumes from a brick kiln Monday.
Nguyen Van Ty, 56, owner of the kiln, his son Nguyen Van Hop, 24, and brother-in-law Vu Van Binh, 41, were found dead by a neighbor.
Ty's wife, Vu Thi Mui, 53, and their son-in-law, Nguyen Van Chung, who fell unconscious at the kiln were rushed to a local medical center.
Four dogs and more than 20 ducks and chickens of the family also died in the accident.
Their neighbor Nguyen Thi Sen said she found the victims lying on the ground when she came to buy eggs at 5 a.m., Dan Tri reported.
"I saw the dogs and chickens lying dead in the front yard"¦ Ty's son lay near the door. I tried to wake him up but he didn't react. His wife Mui was also lying on the ground," said Sen, who then called other neighbors for help.
Police have concluded that the family was poisoned by gas from the brick kiln, which is fueled by a mixture of coal called than to ong (bee hive-shaped coal) in Vietnamese.
Than to ong can produce toxic chemical compounds such as sulfur dioxide (SO2), nitrogen dioxide (NO2) and carbon monoxide (CO).
The kiln next to the house was still burning when the police arrived. Local residents said Ty started making bricks around six months ago and he burned the second kiln on Sunday evening.
Police believe that the toxic fumes from the kiln didn't go up but blew into the house instead as it was cold overnight.
There are hundreds of brick kilns made and operated by the residents in the neighborhood. Police are investigating the matter.