The occupants of the car were proceeding to Salem from Thanjavur when the driver lost control of the vehicle and it fell into the 70-feet deep well.
47-year old Poonguzhali and her 27-year old daughter died while two others were recused by fire and rescue service personnel and local villagers, police said.
The injured had been admitted to a private hopsital in Coimbatore after first-aid at the local Government hospital.