Yesterday morning firefighters were called to the construction site of the Humboldt Forum in Berlin, which is set to open in September, to extinguish a blaze caused by the explosion of a propane gas canister, according to the city’s fire service. Two tar cookers reportedly caught alight, creating a large amount of smoke, although it is reported that the fire was brought under control in 20 minutes without any damage caused to the building. One person was injured and is being treated in hospital.