Thousands of holidaymakers were in danger of missing their flights today after a fatal stabbing halted Tube services to Heathrow airport.
The 18-year-old man died after a fight broke out last night on the platform of Hounslow West underground station on the Piccadilly Line, British Transport Police said.
A London Underground spokeswoman said: "Due to a police investigation, there will be no Tube trains to Heathrow this morning. Travellers should try to find an alternative way to get to the airport.
"I apologise. We are doing all we can. They really have to find an alternative way. We are trying to get some emergency coaches (to run) from Hounslow Central but there will not be enough and they cannot rely on them to get their flights on time."
Each train can carry about one thousand passengers.
A British Transport Police spokesman said officers were alerted by Tube staff at 11.19pm yesterday about a fight involving up to eight men.
One of those, an 18-year-old, suffered stab wounds and later died in hospital.
Two men were arrested near the underground station and were being held at a west London police station.
He said: "As a result of scene examination and searches, Hounslow West underground station remains closed. There will be no Piccadilly Line service between Hounslow West and Heathrow. We have told the underground it could be (closed) up to 1pm."