A person has sadly been hit by a train between Welwyn Garden City and Hitchin.
A spokesperson for Govia Thameslink, which operates the Great Northern line, said: "It is with great sadness that we report a person has been hit by a train between Welwyn Garden City and Hitchin.
"All lines are currently blocked between these stations whilst the emergency services work to deal with this incident."
Trains are currently unable to run between London Bridge and Hitchin.
If you need someone to speak to, the Samaritans are available 24/7 on 116 123.
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