Workmen carrying out roof repairs at the LyonTech-la Doua campus, where 22,000 mainly science students are based, are thought to have accidentally started the blaze. ‘The explosions happened inside the Science Library shortly after 9am,’ said a spokesman for the local prefecture. ‘Sealing work was in progress on the roof the building, and this is how the fire started. An evacuation is underway.’ Speaking just after 10am local time, the spokesman added: ‘At the moment we are only aware of one person who is slightly injured.’