This is the shocking moment Luton airport car park collapsed after an exploding Range Rover sparked a huge inferno.
One hundred firefighters spent 12 hours battling the blaze at the airport's Terminal Car Park Two when the £20million block was engulfed by flames and caved in just before 9pm last night.
Investigators believe the blaze was started when a diesel car suffered an electrical fault or leaking fuel line.
Dramatic footage shows the top floor of the car park collapse and explode after the fire beneath it spread throughout the structure.
Huge plumes of smoke and flames can be seen before a large section of the concrete floor suddenly crumbles and falls, taking dozens of cars with it.
A big bang can then be heard before the flames rise into the air and those filming gasp and swear in horror.
The fire spread as a number of electric vehicles burst into flames in a domino effect, one firefighter suggested.
As many as 1,500 vehicles are feared to have been damaged as a result of the collapse in the car park, which has a capacity of 1,900.
Dramatic footage on CCTV captured the moment the explosion erupted, bringing light fixtures down from the ceiling before a fireball soared through the building.
The vehicle appears to be in the middle of the road used to get around the car park, rather than a designated space.
The car park, which opened in 2019 as part of a £20million modernisation drive, did not have sprinklers, which one fire chief said 'may have made a positive impact on this incident' as he urged the airport to install them in existing and future car parks.
He added that the building's open sides meant the fire will have spread 'horizontally' before it went up through the structure. The inferno burned so hot that the car park building is unsalvageable and will eventually be demolished, sources claimed.
Meanwhile of thousands of airline passengers are suffering disruption as Luton Airport's runway remains closed after a vehicle fire caused a car park to collapse.
The Bedfordshire airport said at 1pm it has reopened its terminal building to passengers and expects flights to resume at 3pm.
A further 27 arrivals were diverted to airports as far away as Cardiff, Liverpool and Manchester, while many other flights were delayed. The figures suggest more than 30,000 passengers have suffered disruption to their journeys.
The fire was declared a major incident, with firefighters working through the night and into the early hours of Wednesday to extinguish the blaze.
Bedfordshire Fire and Rescue Service said it received a report of a car fire on level three of the airport's Terminal Car Park 2 at 8.47pm.
Three firefighters and a member of airport staff were taken to hospital suffering from smoke inhalation, and another firefighter was treated at the scene.
Andrew Hopkinson, chief fire officer for Bedfordshire Fire and Rescue Service, said: 'On arrival my officers were faced with a severe and rapidly spreading fire involving a large number of vehicles that ultimately spread to multiple floors and involved a partial collapse of the car park.'
He said the car park does not have sprinklers, and if it did they 'may have made a positive impact'.
The fire chief added: 'We are already talking to the airport about ensuring that any future, and the existing, car parks have sprinklers fitted.'
Mr Hopkinson said up to 1,500 vehicles were inside the car park at the time of the fire. The blaze is believed to have started with a diesel-powered vehicle 'and then that fire has quickly and rapidly spread', he said.
There is no suggestion the blaze happened intentionally. AA technical expert Greg Carter said the most common cause of car fires is an electrical fault with the 12-volt battery system.
He added that diesel is 'much less flammable' than petrol, and in a car it takes 'intense pressure or sustained flame' to ignite diesel.
A temporary ramp is being installed at the car park to enable undamaged vehicles to be removed.
More footage posted on social media showed flames and smoke tearing through cars.
Russell Taylor, 41, an account director from Kinross in Scotland, saw the fire after flying into Luton Airport from Edinburgh.
He said: 'There were a couple of fire engines with a car ablaze on the upper floor of the car park at just after 9pm.
'A few minutes later most of the upper floor was alight, car alarms were going off with loud explosions from cars going up in flames.
'The speed in which the fire took hold was incredible.'
The car park was opened in 2019 as part of a multi-year modernisation programme costing tens of millions of pounds. Nearby residents were told to close their windows to avoid the smoke.