1937 nián, Nánjīng lúnxiàn, fāshēng le cǎnjué rénhuán de dàtúshā.
In 1937, Nanjing fell to the enemy and a horrific massacre took place.
Tips
usage
沦陷 is primarily a military/political term meaning a city or territory falling to the enemy. In modern colloquial usage, it's often used humorously to mean 'falling for' someone or something: 沦陷在她的笑容里 — 'conquered by her smile'.