An investigation has been launched after an overhead power line collapsed at St Pancras International as a Eurostar train from Paris arrived at the station.
Although witnesses spoke of panic as passengers fled for the exits, none of the 554 people on board were hurt.
Services to and from the Continent were delayed for between one and two hours after the incident on Wednesday evening.
A statement from Eurostar confirmed the power line had come down, and there had been a “loud bang and smoke”. The company said circuit breakers had automatically come into operation to cut off electricity supplies.
“Eurostar is treating this incident extremely seriously and is working with station owners High Speed 1 and Network Rail to identify why this happened,” the statement added..
A spokeswoman for Eurostar said: “All the processes and procedures that we have in place worked well.”