Heathrow Airport was closed on March 21, 2025, due to a fire at a nearby electrical substation that caused a major power outage, impacting flight schedules worldwide. Approximately 70 firefighters spent around seven hours controlling the blaze, which was reported shortly after 11 p.m. local time on March 20. Energy Minister Ed Miliband called the fire "catastrophic," noting that the power backup system had failed and that a backup mechanism was being implemented. Airport officials warned of significant travel disruptions in the days ahead and advised passengers to avoid travel until further notice.