Travellers at Heathrow were affected by a complete break down of Terminal 4’s baggage handling system on Wednesday. Economy class passengers who arrived at the terminal were told they could only take hand baggage with them meaning they either had to leave their luggage behind of miss their flights. Around 4,000 passengers were affected by the problem, with most of them decided to switch airlines or postpone their trip rather than leave their luggage behind. The problem was caused by the automatic baggage sorting system breaking down because of a software failure. It is now the 10th time the baggage handling system has broken down since last May.