A YouTube video from the true-crime channel "this is MONSTERS" examines the 1857 Mountain Meadows Massacre, in which a wagon train of about 120 emigrants was attacked and killed in southern Utah.

The video has drawn 52,598 views in 40 hours (~1,315/hour) and 228 comments. It presents the massacre in the context of Mormon settlers' tensions with the federal government and their conflict with California-bound emigrants during the Utah War.

The massacre was carried out by Mormon militia and Paiute allies under local leader John D. Lee, who was later executed. The Church has acknowledged its members' responsibility and issued apologies, though debates continue over Brigham Young's knowledge and involvement.