A person has been hit by a train between Sheffield and Derby/Alfreton this afternoon.
The sad incident is causing major disruption on trains in the area, according to East Midlands Trains, which said shortly after 2pm that the line was closed in both directions as emergency services attend the scene.
The operator said the line was not expected to fully reopen for another two to three hours, with a normal service expected to resume on the affected routes by 6pm.
East Midlands Trains said: "We regret to inform you that there has been a person hit by a train between Derby/Alfreton and Sheffield.
"This is disrupting our trains on the London St Pancras/Derby/Sheffield and the Liverpool Lime Street/Nottingham/Norwich route."
Virgin Trains East Coast has said it is accepting East Midlands Trains passengers on its services between Doncaster and London Kings Cross until further notice.
East Midlands Trains said its trains are extremely busy and are subject to extended delays and alterations.
It advised passengers to use alternative routes where possible, including:
Sheffield to London Kings Cross via Doncaster
Derby to London Euston via Birmingham
Nottingham to London Kings Cross via Grantham
Leicester to London Euston via Birmingham
British Transport Police has since said that a person has sadly died following the incident at Chesterfield station.