England ? Authorities examined railroad switches Saturday as they tried to determine what caused a high-speed commuter train to derail in northwestern England, sending carriages hurtling down an embankment and killing one passenger.

Safety inspectors were investigating whether the switches had been left in the wrong position, throwing the carriages off the track, said Chief Superintendent Martyn Ripley of the British Transport Police.

Officials were focusing on one set of switches in particular, said Thomas Edwards, lead inspector for the Rail Accident Investigation Board.

The Glasgow-bound Virgin train, carrying 120 passengers and staff, crashed Friday night in countryside near the town of Lambrigg, 270 miles northwest of London. A total of 77 passengers were injured, five seriously.