It's possible that there were simply not enough airport personnel to cope with the wintry mess. A Heathrow spokeswoman said the airport had more than 100 contractors working on clearing snow from the airfield and runway, compared with 140 people on hand at Gatwick, according to The Wall Street Journal. Gatwick handles far fewer passengers than Heathrow, one of the busiest airports in the world.
Meanwhile, Matthews of BAA said that more than 100 extra contractors were brought in to help clear the snow, according to BBC.
UK Prime Minister David Cameron told the Journal that he had offered military assistance to Heathrow, but that the help was declined because the airport needed people who could operate special airport equipment.