When a container holding swine flu exploded on a Swiss train on Monday, it could have led to a nightmare scenario. Luckily the virus was not the mutated swine flu that has killed around 150 people in Mexico and that has already spread to parts of Europe.
The containers were hermetically sealed and cooled with dry ice. However, it seems the dry ice was not packed correctly and it melted during the journey. The gas coming from the containers then built up too much pressure and the ampoules exploded, as the train was pulling into a station.