Joshua 8:25-28 New King James Version (NKJV)

25. So it was that all who fell that day, both men and women, were twelve thousand—all the people of Ai.

26. For Joshua did not draw back his hand, with which he stretched out the spear, until he had utterly destroyed all the inhabitants of Ai.

27. Only the livestock and the spoil of that city Israel took as booty for themselves, according to the word of the Lord which He had commanded Joshua.

28. So Joshua burned Ai and made it a heap forever, a desolation to this day.

Joshua 8