A fall of ground was discovered in the LC3830 SD334 on 7.5.19 around 01:00 hours. This most likely occurred at shift change, durning blast, on 7.4.19 at around 19:00 hours, but is unknown. The heading was previously shot at the end of night shift 7.3.19, & was mucked on day shift 7.4.19. From the time the heading was shot until the fall of ground was likely only 12 hours.