Luton Airport has reopened after a vehicle fire caused a car park to collapse, sparking disruption for tens of thousands of passengers.
The Bedfordshire airport suspended flights from when the fire happened at around 9pm on Tuesday until 3pm on Wednesday.
PA news agency analysis of flight data websites found at least 150 flights due to take off or land at the airport were cancelled.
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 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.
Fifteen fire appliances and more than 100 firefighters were deployed.
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 spokesman for the Association of British Insurers said drivers with fire damage are covered by comprehensive and third-party fire and theft policies.
He added it is “too early to estimate the insured cost of the fire”.
A temporary ramp is being installed at the car park to enable undamaged vehicles to be removed.
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 told PA: “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.
The Dart light rail transit system connecting the airport with mainline railway station Luton Airport Parkway will remain closed even after the runway reopens.
Replacement buses are in operation.
A Polish family said they slept on the floor of the terminal building and on benches after their flight home to Gdansk after a holiday in London was cancelled on Tuesday night.
Agnieske Szmit, 44, said: “We missed our work today, the children should be at school.”
She added: “They tried to evacuate us but they didn’t say where, ‘just go outside and follow the crowds’.”
A woman whose car is stuck in a car park at Luton Airport has told how she saw a fire take hold in a multi-storey soon after her flight landed.
Cristina Cristea, 25, of Towcester, Northamptonshire, was among the passengers whose cars are trapped in Terminal Car Park One, which is next to the car park where the fire happened and is also blocked.
Ms Cristea said she landed at the airport at around 8pm after visiting Romania for her sister’s wedding.
She said: “By the time we came out of the airport it was 9.10pm and we heard more noises and saw flames.
“At first we thought it was shotguns or something as we couldn’t see any flames, then we saw what happened.
“Slowly, slowly they blocked all the access.”
A group of eight Polish university students were stranded at the airport for more than nine hours after their early-morning departure was cancelled.
Nikodem Lesiak, 18, said: “We are tired, and we have spent the whole night here. We need to get to Poland as fast as possible.
“When we got here, we found out Luton is burning and everything is closed.”
