Air-traffic controller Nicola Evans volunteered to work late when her replacement does not turn up. Overworked, she accidentally sends an Aer Lingus jet to taxi onto a runway where a Czech Airlines cargo plane is about to land. However, conflicting instructions are given by the other air traffic controllers in Heathrow's tower. After agonising over her choices, Evans issues an instruction to go-around to the Czech jet, which does so, avoiding the Aer Lingus plane, but colliding with the departing British Airways flight to Bilbao. Unaware that his family were on the British Airways flight, Julian witnesses the explosion as he makes his way back to his car, capturing footage of the disaster on his son's camera. Burning wreckage falls across much of Hounslow and the surrounding area, killing all on board, flattening streets and setting areas of the town and its surroundings ablaze.