Rescue teams are still searching a 17-year-old boy, who fell in Iskar River after he tried to drive a tractor in Bulgaria`s village of Stavertsi on Wednesday evening. The youngster, Iliya Assenov, was working together with his elder brothers in a timber company. The accident occurred after the bigger boys left the cutting area, leaving the victim alone. The boy was moving on a dike until reaching the river`s bed, where the machine heeled over and started sinking. The tractor was found more than a meter under the water surface but its pulling out was impeded by the strong stream.