A string of unusual transactions started to cause alarm at Binance on Thursday afternoon. Binance's top executives put together an informal war room with about 100 participants in response and worked through the night to navigate one of the most damaging crises in Binance's history. The company was forced to halt deposits and withdrawals as more than $6 billion was drained from the exchange. This article details how the hack unfolded based on interviews with people with knowledge of the events and analyses by crypto forensics firms.