German aircraft carrying bombs, and self-propelled rockets like the V2, flew many times across British skies in the war, and especially over London and Kent which are the nearest parts of Britain to continental Europe.
When approaching enemy planes were detected, an air raid siren warned people to go to air raid shelters where the bombs could not reach them. When the raid was over, an all clear signal was sounded.
These air raids did much damage to factories and homes. Firefighters and rescue teams were kept busy, and ambulances rushed injured people to hospital.