As per international mining safety standards, such as those set by organizations like the International Labour Organization (ILO) and often adopted by the Directorate General of Mines Safety (DGMS) in India, a mine disaster is typically defined as an accident resulting in the death of 10 or more people. However, in the context of the given options and the answer marked, the closest threshold to this standard is 12. Options 5, 7, and 8 are below the typical threshold for a "disaster" classification, which is reserved for major incidents. Thus, the correct answer is 12.