Commuters faced disruptions during the morning rush hour on Thursday after a train crashed into an obstruction near Watford, affecting train services to and from Euston. National Rail issued warnings that trains were running at reduced speeds on the line towards Milton Keynes Central, leading to potential delays of up to 45 minutes or service revisions. The disruption was anticipated to continue until 9 am, impacting Avanti West Coast services between London Euston and destinations such as Lancaster, Manchester Piccadilly, Blackpool North, and Glasgow Central. London Northwestern Railway services between London Euston and Tring and Milton Keynes Central were also affected, along with Southern trains operating between East Croydon and Hemel Hempstead. Despite the train crash, the Underground and Overground networks were operating with minimal disruptions, aside from minor delays on the Northern Line due to a train shortage.