Disagree. The book says otherwise: "Israel burned none of the towns that stood on mounds except Hazor" (Joshua 11:13). Jericho and Ai burn earlier in the story (Joshua 6:24; Joshua 8:28). A study Bible, the New Oxford Annotated Bible, notes that Hazor is burned just as Jericho and Ai were. It also notes that Jericho in the south and Hazor in the north mark the two ends of the conquest story.
Michael Coogan and Cynthia Chapman say that for much of the 1900s, scholars overlooked that verse. Digs across Canaan found signs of destroyed towns, especially at Jericho, Lachish and Hazor, and scholars credited the damage to Joshua's army. Later digs at those sites, they say, showed no easy match between the finds and the text.
Learn the Bible.
Not just the stories, but the history, authorship, and scholarship behind it.