On 7^th July 2005 terrorists attacked the transportation system in London detonating four improvised explosive devices. 56 persons died and over 700 were injured, 45 of them critically. These bombings were unexpected and besides causing major injury and loss of life, longer term health effects were reported. A full major incident command structure was put in place led by the London UK Metropolitan Police, and involved other emergency services, the health system and central government. The transportation system of the capital was severely affected with major disruption of the city transportation system for 24 hours. Road traffic became completely gridlocked in the central area with all transport inside the M25 beltway suspended. Communications failures included the breakdown of the mobile phone system due to overload. Despite previous experience with the management of bombing incidents in the UK, the scale of the attacks was significant and caused considerable strains on the emergency response system and public health as well as on the infrastructure of the city.