LONDON — A London-bound passenger train hit a landslide triggered by heavy rain and derailed on Friday, injuring two people and sparking major travel disruption.

Train operator London Midland said part of the train came off the tracks and was hit by an oncoming service near Watford Junction, 20 miles (32 kilometers) north of London, Friday morning.

The ambulance service said medics treated a woman for chest pains and a man for a neck injury. The woman was in stable condition in a hospital, but the man did not require hospitalization.

Trains in and out of London’s Euston station were canceled or delayed.

Several schools and train stations were hit by flash flooding as overnight thunderstorms brought a spell of hot weather to an end across southern England. Other trains were delayed after lightning struck a signal box.

The Met Office weather service said Farnborough, south of London, got 32.8 mm (1.3 inches) of rain in three hours, half the monthly average for September.