Last time London flooded - 1953. Almost 200 people were made temporarily homeless, 1 life lost - died of exposure to gas from a damaged pipe.
Elsewhere in the UK, yes, the UK is not just London, the total death toll on land is estimated at 307 - 38 died at Felixstowe in Suffolk. In Essex, Canvey Island loss of 58 lives. 37 died at Jaywick near Clacton.