Read this and answer the question

Initially the change in strategy caught the RAF off-guard, and caused extensive damage and civilian casualties. Some 107,400 long tons (109,100 t) of shipping was damaged in the Thames Estuary and 1,600 civilians were casualties. Of this total around 400 were killed. The fighting in the air was more intense in daylight. Overall Loge had cost the Luftwaffe 41 aircraft; 14 bombers, 16 Messerschmitt Bf 109s, seven Messerschmitt Bf 110s and four reconnaissance aircraft. Fighter Command lost 23 fighters, with six pilots killed and another seven wounded. Another 247 bombers from Sperrle's Luftflotte 3 (Air Fleet 3) attacked that night. On 8 September, the Luftwaffe returned. This time 412 people were killed and 747 severely wounded.

How many were killed in the bombing of the Thames Estuary?
around 400