A family of three died of gas poisoning early Wednesday in east China's Shanghai, police said.
Police in Putuo District said they received an emergency call at about 9 a.m. from neighbors, who had smelled gas and entered the home, where they found the family unconscious.
The three had stopped breathing when rescuers arrived, police said.
The incident is being investigated, but gas workers said the improper use of a water heater might be at fault.
Neighbors said the three were a couple in their 40s and their teen-age son.