The car dashed against the median and was tossed before turning turtle as Balasubramanian (40), a textile merchant, lost control of the vehicle, police said.
Even as the occupants were trying to come out of the car which got mangled under the impact of the mishap, a speeding Bangalore bound bus hit and dragged the car several feet.
Balasubramanian was crushed to death on the spot while wife Parimala died at a hospital without responding to treatment.
Their two daughters -- Jayasri (3) and Naveena (5) -- escaped with injuries and had been hospitalised.
The family was returning here after attending Pongal festival at Nochipatti near Vedasanthur in Coimbatore district when the mishap occurred.