On Sunday, 11 December 2005, a little after 6 a.m., there was a major explosion at the Buncefield Oil Depot in Hemel Hempstead, Hertfordshire, resulting in the largest peacetime fire in Europe to date. The fire burned for four days before it was extinguished. Several UK government departments and agencies asked the Met Office to provide guidance on the smoke plume — including Defra, the Cabinet Office, various emergency services and the Health Protection Agency. Information on the transport and dispersion of the plume provided by the Met Office assisted with decisions on potential evacuation areas and safe approaches for fire crews and played a vital part in getting people to safe locations.