outbreak
out + break
https://gyazo.com/124aabecd8582014d23faf369eef478f
source: 15 Binge-Worthy Anime To Watch This Weekend!
noun
the sudden or violent start of something unwelcome, such as war, disease, etc.:
【伝染病･戦争･怒りなどの】発生, 勃発, 突発; 【ある事象の】突然の広がり «of» (!時に良いことにも用いる)
e.g. the outbreak of World War II.