Hi,
Probable major short circuit path
PS
Other paths, after cells reaching high temperature may have occurred
The opening ("fused") of connection of plus terminal of cell # 3 to minus terminal of cell # 4 probably spared high current (hundreds of Amps) flowing through # 4 and # 5.
Cells # 4 and # 5 were spared because voltage of plus terminal of cell # 3 went to battery case.
Other paths, after cells reaching high temperature may have occurred.The bad condition of cell # 6 may be explained by a secondary path to battery case.
The major path, in my model "hit severely" cells # 1, # 2 and # 3.
JTSB: