Which Old Testament book details the fall of Samaria?

The book that details the fall of Samaria is Kings. This book narrates the history of the Israelite kingdoms, specifically focusing on the division of the united monarchy into the northern kingdom of Israel and the southern kingdom of Judah. Within Kings, the account of the fall of Samaria—which occurred in 722 B.C.—is documented, emphasizing the events leading to the conquest by the Assyrians and the consequences of the Israelites' disobedience to God.

In contrast, Chronicles primarily recounts the history of Judah and the temple, thus not covering the fall of Samaria. Leviticus focuses on laws and rituals rather than historical events, and Genesis deals with the creation and early patriarchal stories, making it unrelated to the events surrounding Samaria's fall. The specific historical context and detailed accounts within Kings make it the correct choice for this question.