In Season 4, Jack and a CTU team broke into the Chinese consulate in L.A. in order to capture a man who had information about Marwan. In the process, the Chinese guards went trigger happy and shot their own consul.
The Chinese found out Jack was behind it and Logan agreed to turn him over but Cummings ordered a Secret Service agent to kill Jack. That is why Tony, Michelle, and Chloe had to help Jack fake his death.
4,645 posted on 05/22/2006 7:12:21 PM PDT by COEXERJ145
(<--------- Director of CTU Intelligence & Spoilers)