Terrorism Timeline

m. (all times are EDT): A hijacked passenger jet, American Airlines Flight 11 out of Boston, Massachusetts, crashes into the north tower of the World Trade Center, tearing a gaping hole in the building and setting it afire. Plane hits WTC. 9:03 a.m.: A second hijacked airliner, United Airlines Flight 175 from Boston, crashes into the south tower of the World Trade Center and explodes. Both buildings are burning. 9:17 a.m.: The Federal Aviation Administration shuts down …

…m: CNN's Zahn reports that New York City police believe there are people alive in buildings near the World Trade Center. 11:54 p.m.: CNN Washington Bureau Chief Frank Sesno reports that a government official told him there was an open microphone on one of the hijacked planes and that sounds of discussion and "duress" were heard. Sesno also reports a source says law enforcement has "credible" information and leads and is confident about the investigation.