Lucy Mack Smith, mother of the Prophet, was asked to take charge of the exodus of the members from Fayette [May 1831]. When they arrived at Buffalo, New York, they found that the harbor on Lake Erie was clogged with an ice field, and the steamboat carrying the Fayette Saints was unable to leave port. In this difficult situation, she called upon the members to exercise their faith: “Now, brethren and sisters, if you will all of you raise your desires to heaven, that the ice may be broken up, and we be set at liberty, as sure as the Lord lives, it will be done.” At that very moment a noise was heard “like bursting thunder.” The ice parted and a narrow passage formed through which the boat was able to move. They had barely passed through when the avenue again closed, but they were in open water and could continue their journey. Following this miraculous escape, the company was called together in a prayer meeting to offer up their thanks to God for his mercy on their behalf. (Lucy Mack Smith, History of the Church, 240)

Source: Our Heritage, a Brief History of The Church of Jesus Christ of Latter-day Saints, p. 19