No it isn't. The first British civilian death from German bombing was caused on 16 March 1940. Not that this was the catalyst.
The bombing of cities in the Western theater started with the German bombing of Rotterdam on the 14th May 1940. This was explicitly a terror attack which had its desired effect of forcing the Dutch to capitulate.. "Fortress Holland" was forced to surrender due directly to the targeted bombing of its civilians. A point which was not lost on anyone at the time.
The day after this the British abandoned their previous extremely restrictive policy of bombing only military units and started to bomb industrial targets in the Ruhr. The inaccuracy of strategic bombing led to civilian deaths, but these deaths were not the aim of the bombing.
The first German bombs were dropped on London on August 24, 1940. They were almost certainly dropped in defiance of orders, but that didn't make much difference to the people underneath the bombs.
The British attacked the next night with a raid on Berlin, targeting Tempelhof airfield and the Siemens factories in Siemenstad. Hitler then declared (in a famous speech) that if the Royal Air Force dropped so many kilograms of bombs, that Germany would drop a hundred times as many - leading directly to the Blitz.
The whole process of wholesale German v British city bombing kicked off from there.
Ever hear of Guernica?