How did Troy collapse?

After the Trojan city was founded around 3000's B.C.E., it is destroyed several times for many different reasons. The city discovered by Schliemann in 1871 and which he called "burned city", is Troy II period (2500 B.C.E.). In this period when the Trojan treasures were found too, three big and different fires are determined. There were also signs of fire, eartquake and war in other layers. Troy IX, the last settlement, was destroyed by two devastating earthquakes about 500 CE. The fall of Troy VI and VII, that is Homeric Troy, has been muchdiscussed by scholars Dörpfeld claimed that there was eurthquake signs in Troy VI layers. Later, C. Blegen encountered with earthquake signs in layers belong to 1300's B.C.E., late Bronz Age. Considering this damage, he claimed that after a ten years period of succesfully defending itself, the city lost its power with this eartwuake and lost the war.

According to M. O. Korfmann, who tried to solve this question and found that in Troy VIi and VIIa (this classification is made according to the excavation results of Dörpfeld and Blegen), and found evidences that the city was destroyed by a war during 1180's B.C.E. Among findings there were: unburied bodies on the road to the west of castle, unused catapult stones etc.. These findings, although they are not clear evidence of Trojan War, show that the late Bronz Age city was destroyed by war. Whether the invaders were Achaeans is unknown.