Shimla, June 19 -- A 26-year-old woman and her 11-month-old son from Gurugram were killed, and a 52-year-old woman was injured when their tourist vehicle fell into a 200-foot deep gorge in Himachal Pradesh's Lahaul-Spiti district on Wednesday, police said on Thursday. The deceased were identified as Tanu Kumari and her infant son, Daksh Kumar Singh, they added. They were rushed to a hospital in Manali, where doctors declared them dead on arrival. The injured passenger, Savita Devi of Bihar, is undergoing treatment at the Civil Hospital in Manali. According to the police, the accident occurred near Dhara Waterfall, about 4km from Koksar. A group of tourists traveling from Manali toward Rohtang Pass via the Atal Tunnel had pulled over to admire the landscape. While the driver and several passengers stepped out of the vehicle, the two women and the child remained inside. The vehicle suddenly slipped into reverse gear on the incline, rolled backward, and rolled down the steep slope. Local residents rushed to rescue the victims from the wreckage. Investigation into the incident is underway...