Green Park Underground station in London has been closed following a serious incident involving a casualty on the tracks. The British Transport Police responded to reports of the incident at approximately 8:00 AM on April 20. A person has been taken to the hospital with potentially life-threatening injuries. As a result, no trains are running between Waterloo and Finchley on the Jubilee Line, causing significant delays at several stations, including Waterloo, Westminster, and Baker Street. The London Fire Brigade is also assisting emergency services at the scene with two fire engines and a rescue unit deployed. Additionally, the Hammersmith & City line was temporarily suspended due to a separate incident at Paddington station but has since reopened with delays. The situation remains fluid, and authorities are conducting ongoing inquiries into the circumstances surrounding the incident.