A man has died after it is reported he climbed onto a train and was hit by overhead power wires.
Norwich Railway Station is currently closed and emergency services are still at the scene.
Officers from the British Transport Police were called to the Norfolk station shortly after 2am.
Greater Anglia trains are disrupted and major delays and cancellations are expected to continue until at least 11am.
In a statement, BTP East Anglia said: "We remain on scene at Norwich station following a fatality earlier this morning.
"The station is currently closed while enquiries into the incident continue."
Passengers between Norwich and London, Great Yarmouth, Sheringham, Lowestoft and Cambridge were affected. Replacement coaches were laid on and travellers were able to use train tickets on buses.
East Midlands Railway trains are not running between Norwich and Ely, but Greater Anglia is running a reduced service between those routes.
Richard Clinnick, a Norwich-based journalist, was at the station this morning on his way to work and said: "A grim morning here at Norwich Station after a horrible situation overnight.
"Three platforms of impounded trains, including mine, and police still on scene.
"For any angry commuters... just remember someone's family has been ripped apart."
He later added: “The @greateranglia staff are doing a wonderful job at Norwich this morning under trying circumstances."
No details about the man have been released and it is not known if his next of kin has been informed of the death.
