A man has died after two airport vehicles were involved in a "serious accident" on the airfield at Heathrow.
Police and paramedics were called to the scene of the incident shortly after 6am on Wednesday morning, which the airport has said involved two male members of staff.
London Ambulance Service confirmed that one of the men, who was in his 40s and worked as an engineer for British Airways (BA), went into cardiac arrest.
Despite extensive efforts to resuscitate him at the scene and on the way to a west London hospital, he was later pronounced dead.
A Heathrow spokesman 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.
A BA spokesman added: We are deeply saddened by this tragic incident and are offering our full care and support to his family and colleagues.
The other man involved in the accident suffered a suspected broken shoulder and was also taken to hospital.
Police said his injury was not life-threatening or life-changing.
The Health and Safety Executive were informed of the incident, but no arrests were made.
Some passengers were forced to leave their planes as a result of the incident, with delays to a number of flights reported by people on the tarmac and at their gates.
Most of the reported delays were departures from Terminal 5, with BA acknowledging disruption to a small number of our flights.
Heathrow had tweeted earlier that the collision was not expected to cause any impact on journeys today.
A spokesman for the airport added: The airfield remains open and we will work to minimise disruption to our passengers’ journeys.
(c) Sky News 2018: Man dies after ‘serious accident’ involving two vehicles at Heathrow