At a control centre of France's state rail operator SNCF in Saint-Denis, staff are preparing to prevent and manage any incidents on the rail networks during the Olympic Games. This is a colossal task for the centre, which will be responsible for providing services to many of the Olympic venues to the north of the capital. "It's all about prevention," says Severine Lepere, Director General SNCF Reseau Ile-de-France. IMAGES AND SOUNDBITES