According to multiple sources, including ITV News Anglia, The Independent, and ABC News, the cause of the fire at Luton Airports multi-storey car park was a diesel car. The fire started on the third floor of Terminal Car Park 2 and quickly spread, causing significant damage to the structure and hundreds of cars. While the fire was put out by Wednesday morning, the car park partially collapsed and the airport was closed for most of the day, with all outbound flights suspended, inbound flights diverted, and passengers advised not to travel to the airport. There were no casualties, but four firefighters and an airport employee were treated in hospitals for smoke inhalation. The fire service said that a sprinkler system could have helped control the fire, but the car park did not have one.