The bombing of Wieluń is considered by many to be the first major act of World War II, and the September Campaign. After Luftwaffe air units moved into Polish airspace in the early morning of 1 September, they reached the town of Wieluń by 04:40–45. Around this time, the first strikes on the town were conducted, with a total of 46,000 kg bombs being dropped on civilian targets for 9 consecutive hours. Elsewhere, the Battle of Westerplatte and Danzig skirmishes began around the same time (04:45), starting the well-coordinated Invasion of Poland.