Thomas von Essen, New York City's fire commissioner during the 9/11 attacks, has marked the 25th anniversary by recalling the horrors of that day and warning that Britain's current border and migration policies risk creating conditions similar to those that enabled the 2001 terror attacks. Von Essen, now 80, told the Daily Mail that governments must not forget the lessons of 9/11 and criticised what he called the UK's "idiotic" open-door approach to migration, arguing it poses a terrorism risk. His comments carry weight given his direct experience commanding the response to the deadliest terror attack in modern history.

Von Essen lost 343 firefighters under his command when the Twin Towers were struck and collapsed on 11 September 2001, an attack that killed almost 3,000 people in total. He described the confusion of the morning, from initially believing a small plane had hit the North Tower to the realisation, after the South Tower was struck at 9:03am, that America was under coordinated attack. He recounted witnessing one of an estimated 200 to 300 people who jumped from the towers rather than face the flames, and credited the bravery of the FDNY with helping an estimated 15,000 to 18,000 people escape, while reflecting with lasting regret on the initial decision to keep South Tower occupants in place following 1993 bombing protocols.