Judges 9:51
But there was a strong tower within the city, and thither fled all the men and women, and all they of the city, and shut it to them, and gat them up to the top of the tower. But there was a strong tower within the city, and thither fled all the men and women, and all they of the city, and shut it to them, and gat them up to the top of the tower.
The verse belongs to the account of Abimelech's effort to rule Israel after killing his brothers, Gideon's sons. That effort included his destruction of Shechem before his attack on Thebez. During that attack on Thebez all the men and women of the city, all they of the city, fled together to a strong tower within the city for refuge. They shut and barred themselves inside it and climbed to its top or roof.
Abimelech intended to burn the people in the tower as he had burned the inhabitants of Shechem. As his forces were about to do so, a woman struck him mortally with a piece of millstone. After being wounded he hastily asked his armor-bearer to kill him so that people would not say that a woman had killed him.
The surrounding chapter contains Jotham's parable, which shows that the men of Shechem acted foolishly in choosing Abimelech. It teaches that those doing valuable work for God do not seek rule over others. Ambition for exaltation shows lack of qualification to rule.