The controlled detonation of a World War Two (WWII) bomb caused enormous damage in Graz last Friday evening.Explosives experts advised the police to evacuate the main train station of the city and the surrounding area within one kilometre in order to carry out a controlled explosion since it was impossible to safely remove it. The bomb dropped by British fighter jets during WWII was discovered by construction workers carrying out renovation work at the station.Shops, apartments and a retirement home were evacuated before the 250-kilo bomb was blown up. No one was injured, but the explosion caused severe damage to some buildings. Dozens of windows broke and one hand of the old station clock came off, officials said. Rock fragments were hurled into the air by the detonation and later discovered several hundred metres from the station.It is not yet clear who will meet the cost of the damage. Authorities said one option would be to tap into the provincial disaster fund.The Styrian city of Graz was attacked dozens of times by the allied US and British troops in 1944 and 1945. Pilots especially targeted industrial facilities and the areas railway network.Only some days ago, some streets in the Upper Austrian city of Linz had to be evacuated after builders discovered an aerial bomb weighing around 50 kilograms. The aerial bomb was removed by a team of explosives experts who determine that it was harmless since its detonator turned out to be broken.