Heathrow Airport’s terminal 4 was closed and evacuated Monday evening as emergency services responded to an incident.The airport made the announcement in a post on X, urging passengers not to travel to terminal 4 and reassuring that all other terminals are operating normally.The closure comes at Heathrow, located southwest of London, which is the UK’s main international airport and one of the busiest air hubs in the world.“Specialist crews have been deployed to carry out an assessment of the scene, and part of the airport has been evacuated as a precaution whilst firefighters respond,” the fire brigade said, as quoted by AFP.The UK’s National Rail network said in a statement on X that its trains were “unable to call” at the terminal, southwest of London, as a result.This is a developing story…