Rail services between London and Peterborough have been cancelled or delayed after a person was hit by a train.
Disruption on the East Coast Main Line, including on LNER services, was expected until 12:00 BST, Network Rail said.
British Transport Police (BTP) said it had been called to reports of a casualty on the line at Biggleswade in Bedfordshire at 07:00. The person was pronounced dead at the scene.
All lines have reopened but residual delays and cancellations remain.