Sept. 11 timeline

The Sept. 11 timeline lays out key moments from takeoffs through the attacks. American Airlines Flight 11 departed Boston at 8:15 a.m. with 11 crew, 76 passengers and five hijackers aboard. United Airlines Flight 175 left Boston at 8:15 a.m., while United 93 took off from Newark at 8:42 a.m. after a traffic delay. Between 8:46 and 9:05 a.m., hijackers crashed Flight 11 into floors 93–99 of 1 World Trade Center and later struck Flight 175 into floors 77–85 of the South Tower. President George W. Bush was alerted at 8:50 a.m. and learned of a second plane by 9:05. The Pentagon was hit at 9:37 a.m. South Tower collapsed at 9:59 a.m.; Flight 93 crashed near Shanksville at 10:03 a.m.; and the North Tower collapsed at 10:28 a.m.