Nov 5 (Reuters) - The U.S. Senate has rejected a measure that would have required prisoners charged with involvement in the Sept. 11 attacks to stand trial in a military court rather than a criminal court. Here are some facts about the detention center on the U.S. naval base at Guantanamo Bay, Cuba, and the fate of those held there.

* The Guantanamo detention camp was set up in January 2002 to hold foreigners captured after U.S.-led forces invaded Afghanistan to root out al Qaeda and its Taliban protectors in response to the attacks of Sept. 11, 2001, that killed nearly 3,000 people in New York, Washington and Pennsylvania.

* The United States holds 215 prisoners at Guantanamo and has released or transferred to other governments more than 550 others. Twenty-five of those were released under the Obama administration and the rest were released under the Bush administration.

* Six captives have died in custody at Guantanamo -- one from cancer and five from suicide.

* Two Guantanamo prisoners have been transferred to the United States. Yaser Hamdi, who was born in Louisiana to Saudi parents, was moved to a naval brig in South Carolina in 2002 when the military learned he was a U.S. citizen. He was held without charge for two years and then deported to Saudi Arabia in 2004 after the U.S. Supreme Court upheld his right to challenge his detention. The other, Tanzanian citizen Ahmed Khalfan Ghailani, was sent to New York in June 2009 to stand trial in a civilian court on pending charges of conspiring in the 1998 bombings of U.S. embassies in Tanzania and Kenya, which killed 224 people.

* Only three trials have been completed in the special military tribunals at Guantanamo. Two prisoners were convicted of providing material support for terrorism, held for a few more months at Guantanamo, then sent home to Australia and Yemen. The Obama administration says those convictions are unlikely to withstand appeal because that charge was not classified as a war crime when the acts were committed. The third, also a Yemeni, is still at Guantanamo, serving a life term for conspiring with al Qaeda, soliciting murder and providing material support for terrorism. (Reporting by Jane Sutton; Editing by Xavier Briand)