An emergency timetable has been put into place after major disruption on rail services from Hertfordshire, Cambridgeshire and Norfolk into London's King's Cross.
Urgent engineering work is taking place in the Alexandra Palace area of north London.
First Capital Connect is operating an amended timetable. It affects services to and from places like King's Lynn, Ely, Cambridge, Peterborough, Stevenage, Letchworth and Royston.
More top news
Cloudy, coastal drizzle later tonight. Breezy near the coast
Fine and dry with sunny spells. Breezy near the coast.
The family of a missing woman from Milton Keynes has been told a body has been found in a wood in Hertfordshire.