1. Attack on the World Trade Center September 11, 2001 8:45 am EDT Photos by Eric Cheong

2. Before

10. World Trade Center Attack From the CNN Web site

11. September 11, 2001 -- 8:45 a.m. EDT American American Airlines Flight 11 hijacked from Boston, Massachusetts, slams into the World Trade Center's north tower in Manhattan.

12. September 11, 2001 -- 9:03 a.m. EDT A second plane, United Airlines Flight 175, crashes into the World Trade Center's south tower, causing a massive explosion.

13. Jet fuel and debris engulf the towers.

14. September 11, 2001 -- 9:30 a.m. EDT President Bush calls the explosions an "apparent terrorist attack" and leads the nation in a moment of silence for the victims.

15. As the towers burn, debris rains down on the streets of Manhattan.

16. September 11, 2001 -- 10:00 a.m. EDT Weakened and billowing with smoke, the south tower collapses.

17. Chaos ensues on the streets below as emergency workers try to get people out of the city.

18. With the south tower down, the north tower continues to burn.

19. Shocked onlookers can only watch in horror.

20. The north tower begins to crumble.

21. September 11, 2001 -- 10:29 a.m. EDT The WTC's north tower collapses.

22. People run in terror as smoke from falling debris billows behind them.

23. Clouds of smoke obstruct the place where the WTC once towered over the New York skyline.

24. A thick layer of ash and soot blankets the city.

25. Covered with ash and soot, shocked survivors flee in New York.

26. Billowing smoke trails out to the Statue of Liberty. President Bush states: "We will do whatever necessary to protect America and Americans... The United States will hunt down and punish those responsible for these cowardly acts."

27. WTC Second Attack September 11, 2001

28. September 11, 2001 -- 9:03 a.m. EDT A second plane crashes into the WTC

43. More slides

44. The images posted on CNN’s web site before 10:00 am on the day of the attack (9/11/01). The web site became so overloaded, it was impossible to get more information there until many hours later.

45. Escaping from WTC building 2, this guy took pictures on the way out. This is the lobby.

46. From the WTC lobby, looking up at the people evacuating.

48. Sunrise over Manhattan, the morning after (9/12/01)

49. Moments after the second plane hit the south WTC tower.