Joshua 8:27-29
27 But Israel did carry off for themselves the livestock and plunder of this city, as the Lord had instructed Joshua.
28 So Joshua burned Ai and made it a permanent heap of ruins, a desolate place to this day.
29 He hung the king of Ai on a tree and left him there until evening. At sunset, Joshua ordered them to take his body from the tree and throw it down at the entrance of the city gate. And they raised a large pile of rocks over it, which remains to this day.