William Clayton records Emma Smith and others sending messengers to convince Joseph to "give themselves up," citing a concern that "the city would be destroyed and the people massacred."
William Clayton, "An Interesting Journal," The Juvenile Instructor 22 (April 15, 1886): 122
On receiving this information the President and one or two others concluded to leave the city and go over to Iowa in the night.
During the day following some of the brethren, with Sister Emma Smith, despatched messengers to request the President and those with him to come and give themselves up, fearing that the city would be destroyed and the people massacred if they did not do it.
About five o'clock, p.m., the little party returned and concluded to surrender, although it was contrary to the President's feelings to do so.