Being 'Bombed Out'

My Nan and Granddad lived in the East End of London, during the war, together with their four children, Bill, Fred, Jim and Sylvia (Sylvia being my Mum). My Granddad was not called up to fight as, I believe, he worked in a factory producing something for the war (not exactly what).

My Nan took the three youngest children with her, during the worst of the bombing, to stay with her sister and family in Normandy, Guildford. It was quite a surprise and shock, therefore, when, one day, they spotted my Granddad walking down the hill towards their house. He was wearing his pyjamas and slippers, and over this his black coat and bowler hat. He was pushing his bicycle, and, attached to the bicycle by a lead, was the family dog. My Granddad's house had been bombed, and he had nothing left, apart from the few things that he had with him. I believe he had been in the air raid shelter in the garden, but the dog had been in the house and had survived by hiding under the bed.

I'm not sure at what stage of the war this happened.