The deceased were identified as C Pushpalakshmi of Ponni Nagar in Pammal near Pallavaram and her grandson Vishal. Her husband Chokalingam (61) and daughter Mallika (38) are admitted to the hospital. Police said Chokalingam works in the Chromepet GH.
On Wednesday night, to smoke out mosquitoes, Chokalingam took an empty steel can and burnt charcoal in it. He then closed all the windows and turned on the air-conditioner and went to bed with others.
Usually, Chokalingam and Pushpalakshmi would wake up and open the main door at 6 am and start their daily routine. On Thursday, the neighbours noticed their doors shut even after 7.30 am and since there was no response after knocking on the door informed Chokalingam’s son Velu, who is also residing in the same locality.
Velu broke open the door with the help of neighbours and found the house filled with smoke and all four lying unconscious in the room. He soon rushed them to Chromepet Government Hospital where Pushpalakshmi was declared brought dead while the other three were shifted to the Chennai RGGGH in a critical condition. Later in the day, Vishal too succumbed.
Shankar Nagar police held inquiries and registered a case. After the initial inquiry, police said the deaths were because of asphyxiation and further details are awaited in the post-mortem report.