qún​tǐ​xìng​shì​jiàn

mass incident

  1. group
    A community or collection of individuals who share common characteristics; a social group or class.
  2. xìng affix
    [-ity]
    Suffix used after verbs or adjectives to form nouns expressing a state, quality, or scope, similar to English "-ity", "-ness", or "-ism".
  3. event
    incident; event; a major occurrence in history or society