On June 27, 1844, Hyrum and Joseph Smith were murdered by an angry mob. We testify that they were men of God.
"Joseph Smith, the Prophet and Seer of the Lord, has done more, save Jesus only, for the salvation of men in this world, than any other man that ever lived in it. In the short space of twenty years, he has brought forth the Book of Mormon, which he translated by the gift and power of God, and has been the means of publishing it on two continents; has sent the fulness of the everlasting gospel, which it contained, to the four quarters of the earth; has brought forth the revelations and commandments which compose this book of Doctrine and Covenants, and many other wise documents and instructions for the benefit of the children of men; gathered many thousands of the Latter-day Saints, founded a great city, and left a fame and name that cannot be slain. He lived great, and he died great in the eyes of God and his people; and like most of the Lord’s anointed in ancient times, has sealed his mission and his works with his own blood; and so has his brother Hyrum. In life they were not divided, and in death they were not separated!" Doctrine & Covenants 135:3
"Although the events of June 27, 1844 were tragic, we are provided comfort as we realize that Joseph Smith's Martyrdom was not the last chapter in this account. Although those who sought to take his life felt that the Church would collapse without him, his powerful testimony of truth, the teachings he translated, and his declaration of the Savior's message go on today in the hearts of members throughout the world, who proclaim him a prophet of God." --President Thomas S. Monson