Why is 4 unlucky in China?

Why is the number 4 considered unlucky in China?

The digit 4 (四, pinyin: sì; Cantonese Yale: sei) is often viewed as an inauspicious number, especially among Cantonese speakers. This is primarily because its pronunciation closely resembles the word for "death" (死, pinyin: sǐ; Cantonese Yale: sǐ). As a result, many people tend to avoid this number due to its negative connotations.