 They can leave without force or injury to themselves or their property, but I say unto you with all candor, they shall go. They may fix the time within 60 days, or I will fix it for them. Saturday, September 12, 1846. Vigilante leader Thomas Brockman demanded unconditional surrender of those arrayed to defend Nauvoo. The saints refused. And at 1 p.m., Brockman attacked.