Between 0815 and 0830 BST on May 3, 2004, the Sasser worm infected the systems controlling the check-in, baggage handling and boarding at British Airways and caused the lost of use of around half its check-in desk computers at Heathrow’s Terminal Four.

Twenty British Airways flights were each delayed about 10 minutes due to Sasser troubles at check-in desks. A total of 21 flights to Isreal, the Middle East, the US and East Africa were affected. The terminal was back to its normal timetable by 1200 BST. (#1)