Money for the pilots was routed by an al Qaeda operative in Dubai named Moustaffa Ahmed al-Hazemi, according to U.S. investigators. On March 1, Essabar and Binalshibh moved out of the apartment on Marien Street, leaving it cleaned.
The plotters continued to travel in and out of the United States. Atta, Al-Shehhi and Jarrah all crossed the Atlantic repeatedly. Investigators in Spain have in the last year broken up an al Qaeda cell that they now believe facilitated planning meetings that Atta attended in the country in January and July 2001.
Authorities remove boxes from firm owned by a German Syrian in Fitzbek, northern Germany, as part of the continuing investigation into the Hamburg cell.
Mohammed Zammar, the Hamburg recruiter, may have played a role in the still mysterious meetings in Spain. In 1991, Zammar met a Spanish Syrian radical, Abu Mosab Souri, or Mostafa Abdel Kader Miriam, according to an Arab intelligence agency. The two men remained in contact through 2000.
Over the summer, the 13 hijackers known as "the muscle" began to arrive in the United States. Bin Laden himself appears to have had a role in directly choosing these hijackers, and he clearly wanted Saudis. "They were selected for their fervor, their discipline and their nationality," said one Arab official.
Zuher Hilal Mohamed al Tbaiti, a Saudi arrested in Morocco for planning an attack on U.S. and British ships in the Strait of Gibraltar, has told his interrogators that bin Laden had once considered him for the Sept. 11 plot, according to Moroccan intelligence officials.
Tbaiti, who had lived in New York for about six months in 1999 and was later trained in explosives in Afghanistan, quoted bin Laden as saying, "I want you for a mission in the United States." But al Qaeda later rejected him as undisciplined, according to the debriefing in Morocco of Tbaiti and alleged accomplices captured there.
The Saudi government, without providing any hard evidence, asserts that the Saudi "muscle" was recruited outside Saudi Arabia after these men had left to fight in Chechnya. The Saudi interior minister, Prince Nayef, said in an interview that he also believes most of these late volunteers did not know they were going to die on Sept. 11.
But the government offered little support for its theses. In interviews at the Interior Ministry in Jiddah, Saudi officials said their files on the 15 Saudi hijackers consisted only of basic biographical material such as date of birth, employment and marital status, date of passport issue and when they left the kingdom.
An alleged al Qaeda video released to al-Jazeera and broadcast Tuesday suggests, however, that the Saudi volunteers knew exactly what they were doing.
Abdulaziz Alomari, a graduate of an Islamic college in the Saudi province of El Qaseem, disappeared in early 2001, leaving a wife in the city of Al-Baha, according to Saudi officials. On Sept. 11, he walked behind Atta as they were filmed going through airport security in Portland, Maine, on their way to Boston's Logan airport.
Apparently referring to his last testament, Alomari said on the video: "I am writing this with my full conscience and I am writing this in expectation of the end, which is near. An end that is really a beginning.
"We will get you. We will humiliate you. We will never stop following you," he continued. "God praise everybody who trained and helped me, namely the leader Sheik Osama bin Laden. May God bless him. May God accept our deeds."
By August 2001, his disciples departed, bin Laden began to speak to followers of a dream he had, according to Tbaiti, the prisoner in Morocco. "He said he saw America in ashes," Tbaiti told his interrogators. "It was like a prophecy."
Only three members of the Hamburg cell -- Atta, Jarrah and Al-Shehhi -- died on Sept. 11. Essabar, Bahaji and Binalshibh fled Germany shortly before the attacks; all three are being sought on an international arrest warrant issued by German officials. Motassadeq was indicted in Germany last month on at least 3,116 counts of accessory to murder.
As for Zammar, the recruiter, he was arrested in Morocco last year and deported to Syria, where he is being interrogated.
One year later, families of the hijackers, whether in Saudi Arabia or Hamburg, remain in a state of angry denial.
Neshe Bahaji, Said Bahaji's widow, emerged recently from behind the door of her new apartment holding her 18-month-old son, Omar. She was forced out of her last apartment in Hamburg because of the infamy of her husband. She last saw him on Sept. 3, when he told her he was going to Pakistan for two months to take up an internship with a computer company.
Before departing, he went to the mosque, and returned with his hair cropped short, she said.
"My husband is innocent," she said, a head scarf enclosing her pale face. She believes he is alive. In June, her mother-in-law received a telephone call that she said was a greeting from Bahaji relayed by an unknown voice on the other end of the line.
Now he is afraid to come home, Neshe Bahaji believes.
"This whole theater is predestinated," she said, feeding her son a spoonful of rice. "Allah gives me strength to endure. It is a test."
Special correspondents Souad Mekhennet in Hamburg and Shannon Smiley in Berlin contributed to this report.