For those wondering why the character for hair (发) is involved, keep in mind that simplified Chinese has homographs—two different characters that are written the same way and are considered identical. In traditional Chinese, the character for hair is 髮. 发生 in traditional Chinese is 發生. Still, 發 and 髮 are homophones in Chinese.
They're only homophones if you ignore tone ;) 发<發 is fā, while 发<髮 is fà (fǎ in Taiwan) or in some words toneless fa
This is the first time I am seeing a language where "What happened?" uses six syllables. Are there shorter sentences that mean the same as "发生了什么事"? Also, can "事" be omitted?
Actually, I often hear 发生omitted. People just say 什么事？ Although that normally means What's the matter? To say What happened? people would say 怎么了？