Kanpur, Jan 23 : An elderly couple and their son died after they inhaled smoke from a makeshift fireplace in their home in the Juhi locality of Uttar Pradesh's Kanpur. The police said that the cause of death was asphyxiation. Puran Chand Sharma, 80, his wife Mithlesh Sharma, 78, and their son Narendra Sharma, 52, died in their sleep after they left the fire burning throughout the night. They were discovered motionless in the morning on Monday after which family members rushed them to a hospital where they were declared dead on arrival. Two others who were also in the room, Nimisha, 20, and Dhruv, 18, were also hospitalised. The elderly couple's younger son Sudhir said the condition of Nimisha and Dhruv was stable. 'The fire was left burning at the insistence of parents who needed its warmth due to the cold,' he said. DCP South Ravindra Kumar said a forensic team was examining the incident site. /IANS