A high-speed passenger train ploughed through trees and dirt "like a bulldozer" after it mysteriously derailed in north-east Australia on Tuesday, injuring nearly all 163 people on board, rescue workers said. As a major investigation was launched, ambulance officials expressed amazement that no one onboard the "City of Townsville" express was killed, although six were airlifted for treatment and another 29 driven by ambulance with spinal, pelvis and other serious injuries.