When and where did it happen that the Twin Towers were collapsed?

The NYPD (New York Police Department) logs the first tower's (South) collapse at 9:59 a.m., and the second tower's (North) at 10:28 a.m.

The Twin Towers collapsed 29 minutes apart from each other.
The Twin Towers of the New York World Trade Center collapsed at 9:59 AM and 10:28 AM EDT on September 11, 2001.

The buildings were targeted as part of a terrorist campaign against the United States by Islamic fundamentalists opposed to the US actions in the Middle East. The attack was funded in part by the Al Qaeda movement led by Osama bin Laden (also Usama), a Saudi expatriate who became active in guerrilla and terrorist movements.

The attacks on the Pentagon, in NYC, and in Pennsylvania took place on September 11, 2001. At 8:46 AM EDT, American Airlines Flight 11 was crashed into the World Trade Center's North Tower, followed by United Airlines Flight 175, which hit the South Tower at 9:03 AM. The South Tower collapsed less than an hour later at 9:59 AM, followed by the North Tower at 10:28 AM. As many as 2750 people, including the hijackers and passengers of the two planes, were killed.
September Eleventh, 2001. Known as 9-11 because September is the ninth month and it happened on the eleventh day.
September 11, 2001
Tuesday September 11, 2001.
The Twin Towers fell on Tuesday September 11th, 2001.

At 8:46 a.m., American Airlines flight 11 crashed into the World Trade Center's North Tower, followed by UA flight 175 that hit the South Tower at 9:03 a.m.

The south tower (2 WTC) fell at approximately 9:59 a.m., after it had burned for 56 minutes. The North tower (1 WTC) collapsed at 10:28 a.m., after it had burned for approximately 102 minutes.