Some 40 people fled a 21-storey building in south-east London yesterday after a fire broke out on the 17th floor. Firefighters were sent to battle the blaze which was rumoured to have been caused by lightning. Meanwhile a 25-year-old teaching assistant survived unscathed after he was knocked to the ground by a lightning strike at Hackbridge Primary School in Sutton, south London, yesterday afternoon. Departing flights at Gatwick Airport were suspended after lightning struck an air traffic control tower while train services between London and Brighton were disrupted due to a lightning strike between Horley and Three Bridges.