A major airport fire disaster was avoided at Heathrow's Terminal One yesterday through a mixture of luck and good planning.
The luck was that the 4.40 a.m. fire broke out in a Burger King restaurant when there were no passengers in the terminal.
The good planning was shown in the installation of a £1 million fireproof membrane in the terminal roof which restricted the flames which had spread through ducting from the restaurant.
A fire safety expert said an evacuation would have been chaotic had the fire started just a few hours later when the terminal would have been packed.
No-one was hurt but more than 300 Heathrow flights had to be cancelled, stranding thousands of passengers in Ireland, Britain and on the Continent. The incident led to traffic chaos in and around the west London airport, with would-be passengers abandoning their cars to try to get to their flights.
Even when the terminal reopened for flights in the early afternoon, there were long check-in queues, delays and passenger complaints. And with airline crews and aircraft displaced by the disruption, delays are expected to continue this weekend.
It was five hours before the fire was finally put out, although Heathrow officials stressed that at no time was the fire out of control. But it is estimated that the damage will run to hundreds of thousands of pounds and both the London Fire Service and the British Airports Authority will conduct inquiries.
"It was extremely fortunate that the fire was very early in the day. Two hours later, the terminal would have been packed and there could have been a chaotic evacuation," said Prof Ed Galea, director of the fire safety engineering group at the University of Greenwich, south London.
"If there are any lessons to be learnt, we shall take them to heart," said Heathrow's safety and security director, Mr Paul Fox. "The fact that we had the terminal open again so soon after the fire proves that our safety plans were in good order."
Some 307 flights were cancelled at Heathrow - about two-thirds of them being operated by British Airways. Services did operate from the airport's other three terminals but were subject to delays.
By 3 p.m., Terminal One was handling both arrivals and departures, but passengers were still suffering.
BA, which would normally have operated 334 flights in and out of Terminal One yesterday, managed to finally get flights away at 3 p.m., while British Midland, which would normally operate 200 flights, began at 3.30 p.m. Both airlines warned passengers to expect delays on some flights.
Other airlines caught up in yesterday's disruption included Aer Lingus, the Belgian carrier Sabena, and South African Airways.
Terminal One alone handles enough passengers - about 22 million a year - to make it the fifth busiest airport in Europe.
Mr James Laird, a spokesman for Burger King, said: "We have unsubstantiated reports that the fire started in the roof void near the Burger King restaurant.
"The source of the fire is not yet known. It is believed that Burger King staff were the first to notice smoke coming through the communal duct work above the restaurant and our own fire suppression system was activated."
A Labour MP, Mr Andrew Mackinlay, has tabled Commons questions calling on the government to order a full inquiry.