A man has died at Heathrow, after a "serious accident" involving two vehicles on the airfield.
Passengers were evacuated from planes earlier. Two members of staff driving vehicles were involved in the collision on the taxiway just after 06:00AM, the Met Police said.
One man, aged in his 40s, was taken to a west London hospital and has since died. Another man was treated at the scene.
"Officers have informed next of kin. We await formal identification," the police said.
"A post-mortem will be scheduled in due course. There have been no arrests. The Health and Safety executive has been informed."
Officers from the Met’s Serious Collision Investigation Unit are investigating
A Heathrow spokesperson said: "We can confirm that following a serious accident involving two vehicles on our airfield, an airport colleague has passed away. Our deepest condolences go to the family and friends affected by this accident. We will be fully cooperating with the police in the investigation which will follow."