LAYYAH: At least 11 people lost their lives and about 20 people were left injured after a passenger bus hit a tractor trolley due to over speeding. According to sources the vehicle sped out of control and hit the the trolley resulting in the instant death of 11 people and left several others seriously injured. The bus was on its way to Rawalpindi from Karachi meanwhile the injured have been shifted to District Headquarters Hospital.