This video was released yesterday on the fifth anniversary of the attacks. Not much information is known about it at present but it obviously documents the World Trade Center attack from a nearby building. The second plane hitting the tower and the first collapse is edited out but the north tower collapse is included. Rescue efforts, including footage of a rescue helicopter is also shown.
The shocked onlookers remark their surprise that fighter jets are not in the air defending the area.
The second plane is described as a "military plane" - something the CGI theorists will enjoy - but my first reaction upon seeing the second plane video on 9/11 was also that it was a military plane - because the sight of a commercial airliner crashing into a building was unprecedented and the first presumption was that the plane was in the sky to observe the fire in the north tower and/or conduct escue efforts.