They received visas in Saudi Arabia sometime before 2000 (ABC News and Wikipedia).

abcnews.go.com/WNT/story?id=130051&page=1

A new report accuses the State Department of staggering lapses in its visa program that gave Sept. 11 hijackers entry into the United States.

The political journal National Review obtained the visa applications for 15 of the 19 hijackers — and evidence that all of them should have been denied entry to the country.

Almost all of the hijacker’s visas were issued in Saudi Arabia, at the U.S. Embassy in Riyadh or the U.S. Consulate in Jedda. Terrorist ties aside, the applications themselves should have raised red flags, say experts. The forms are incomplete and often incomprehensible — yet that didn’t stop any of the 15 terrorists for whom the visa applications were obtained from coming to the United States.

The only alleged would-be hijacker who failed to get a visa was Ramzi Binalshibh, who was denied entrance to the United States repeatedly.

“This is a systemic problem,” said Nikolai Wenzel, a former U.S. consular officer. “It’s a problem of sloppiness, it’s a problem of negligence which I would call criminal negligence because obviously, having reviewed all these applications, there is a pattern here.”

The pattern? None of the 15 applications reviewed was filled out properly.

Brothers Wail and Waleed al Shehri applied together in October 2000. Under “occupation” Wail wrote “teater;” brother Waleed claimed “student.” The name and address of alleged employer and school was listed as “South City,” and the questionable U.S. destination named as “Wasantwn.”

Visas approved.