A train collision north of London has resulted in one fatality and at least 89 injuries. The incident occurred when one train impacted the rear of another, causing a carriage to derail. A passenger described the impact as immediate. Emergency services are currently at the scene providing assistance and investigating the cause of the crash. Authorities have not yet released details regarding the extent of the injuries sustained by those involved, but confirm multiple people have been transported to local hospitals. Rail services in the area have been suspended as investigations continue and recovery efforts are underway.