Baku, February 18, AZERTAC At least 31 people were killed and another 15 injured after a public transit bus plunged into a ravine along the highway connecting western Bolivia's departments of Potosi and Oruro, according to Xinhua."There are 31 people who lost their lives in this incident. We are still recovering the bodies," Colonel Limbert Choque, spokesman for the departmental police command in Potosi, told local media.Preliminary police reports indicate that the bus driver lost control of the vehicle before it veered off the road and fell into an 800-meter-deep ravine on Monday.Choque said the stretch of road where the tragedy occurred has sharp curves and steep slopes that increase the risk of accidents.Among the injured are four minors, two of whom are in critical condition and receiving intensive care. The remaining 11 are adults, including two who are undergoing surgery for severe injuries, reports said.