where is the tunnel located?
Beneath the English Channel at the Strait of Dover.
Channel Tunnel
The Channel Tunnel (), also referred to as the Eurotunnel or Chunnel, is a railway tunnel that connects Folkestone (Kent, England, UK) with Coquelles (Hauts-de-France, France) beneath the English Channel at the Strait of Dover. 
what is grayrigg derailment? A fatal railway accident. where did it happen? To the south of Grayrigg, Cumbria, in the North West England region of the United Kingdom. what happened actually? The train derailed at 20:15 at a faulty set of points almost immediately after crossing the Docker Viaduct .The rear half of the train would still have been crossing the bridge whilst the front derailed at the points. what caused it? A report by the Rail Accident Investigation Branch stated that the immediate cause of the accident was the condition of the stretcher bar arrangement at points 2B at Lambrigg crossover, which resulted in the loss of gauge separation of the point switch blades. were there any fatalities? Yes, one . when was the investigation branch created? In 2005. what was the objective? To independently investigate rail accidents in the United Kingdom and the Channel Tunnel in order to find a cause, not to lay blame.
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Channel Tunnel [SEP] Introduction
The Channel Tunnel (), also referred to as the Eurotunnel or Chunnel, is a railway tunnel that connects Folkestone (Kent, England, UK) with Coquelles (Hauts-de-France, France) beneath the English Channel at the Strait of Dover. It is the only fixed link between the island of Great Britain and the European mainland. At its lowest point, it is deep below the sea bed and below sea level. At , the tunnel has the longest underwater section of any tunnel in the world, and is the third longest railway tunnel in the world, being just 150 metres longer than the Yulhyeon Tunnel.