Accused 9/11 plotters reach plea deal, Pentagon says

• "The specific terms and conditions of the pretrial agreements are not available to the public at this time," per a U.S. Defense Department statement.
• The three men were facing a death penalty trial over the attacks that killed 2,977 people. A Pentagon spokesperson declined to comment further on the U.S. Defense Department's public statement.

Zoom in: After initially being charged jointly and arraigned with the other accused 9/11 plotters, Ali Abdul Aziz Ali and Ramzi Bin al Shibh, the three men who will plead guilty over the attacks were again charged jointly and arraigned for a second time in 2012.

• Mohammed has been held at Guantánamo since at least 2006 following his capture in Pakistan in 2003.

Context: During the deadliest terrorist attack on U.S. soil, terrorists with links to Al-Qaeda hijacked four planes and crashed two of them into the Twin Towers of New York City's World Trade Center, killing 2,753 people, and a third into the Pentagon, where 184 others died.

• Crew members and passengers on the fourth plane that was headed toward D.C. learned about the other attacks and attempted to retake the plane from hijackers, which resulted in 40 people dying. It was crashed in a Pennsylvania field.

Go deeper: America remembers 9/11, more than two decades later

Editor's note: This article has been updated with new details throughout.