What caused USDT to crash?

Could you please elaborate on the factors that led to the collapse of USDT? I understand that it's a stablecoin pegged to the value of the US dollar, but what exactly went wrong? Was it due to a lack of liquidity, market manipulation, or some other underlying issues? How did this affect the overall cryptocurrency market, and what are the implications for investors and market participants? Thank you for your time and expertise.