According to latest reports six people were killed, 18 sustained life-threatening injuries and up to 70 others were injured in today's train crash at Potters Bar station in Hertfordshire.
The four-carriage train, which was carrying 150 passengers, derailed and hit a platform at the station on its way from London to Norfolk.
The train is said to have destroyed much of the modern station which includes four platforms and various modern buildings.
It also damaged a footbridge, which later partially collapsed, where the rail tracks go over a main road.
Reports say that vehicles may be trapped beneath the collapsed bridge, and that there are still people trapped inside the train.
The Hertfordshire Police issued a statement saying: "This is being treated as a major incident and we are responding as a matter of urgency."
The reason for the crash is as yet unknown. The driver, who escaped unhurt, is helping the authorities to determine its cause.
The West Anglia Great Northern (WAGN) service was the 12.45 train travelling from London King's Cross to King's Lynn in East Anglia.
Two emergency numbers have been issued for those concerned about friends or relatives who may have been on the train: 00 44 (0)1707 354158 or 00 44 (0)845 944 1551.
The scene of the crash is less than five miles from the site of the Hatfield crash in 2000 in which four people were killed.
Two staff members from Cunningham Lindsey's specialist adjusting network have been sent to the crash site.
