Hijackers aboard United 175 (South Tower) were:

Marwan Al-Shehhi,

Fayez Rashid Ahmed Hassan Al Qadi Banihammad,

Ahmed Alghamdi,

Hamza Alghamdi, and

Mohand Alshehri.

Aboard American 11 (North Tower) were: Satam M. A. Al Suqami,

Waleed M. Alshehri,

Wail M. Alshehri,

Mohamed Atta*, and

Abdulaziz Alomari.

My understanding is that Atta was the leader.

American Airlines Flight 11:

Mohammed Atta

Waleed Al Shehri

Wail Al Shehri

Abdulaziz Al Omari

Satam Al Suqami

United Airlines Flight 175:

Marwan Al Shehhi

Fayez Banihammad

Hamza Al Ghamdi

Ahmed Al Ghamdi

Mohand Al Shehri

American Airlines Flight 77:

Hani Hanjour

Majed Moqed

Khalid Al Midhar

Salem Al Hazmi

Nawaf Al Hazmi

United Airlines Flight 93:

Ziad Jarrah

Ahmed Al Haznawi

Saeed Al Ghamdi

Ahmed Alnami

Hope this helps.

The people responsible were named Mohamed Atta, Marwin al-Shehhi, Ziad Jarrah, Waleed al-Sheri, Wail al-Shehri, Abdulez al- Omari, and Santam al- Suqami. They were members of the group al-Qaeda.

The hijackers of American Airlines Flight 11 (crashed into the north tower) were:

Mohamed Atta

Waleed al-Shehri

Wail al-Shehri

Abdulaziz al-Omari

Satam al-Suqami

United Airlines Flight 175 (crashed into the south tower):

Marwan al-Shehhi

Fayez Banihammad

Mohand al-Shehri

Hamza al-Ghamdi

Ahmed al-Ghamdi

American Airlines Flight 77 (crashed into the Pentagon):

Hani Hanjour

Khalid al-Mihdhar

Majed Moqed

Nawaf al-Hazmi

Salem al-Hazmi

United Airlines Flight 93 (crashed in the Pennsylvania field):

Ziad Jarrah

Ahmed al-Haznawi

Ahmed al-Nami

Saeed al-Ghamdi