National Air Cargo told the ABC a shocking YouTube video purportedly showing a deadly plane crash at Bagram Air Field in Afghanistan is believed to be authentic.
Seven US aviators have died in the crash. The Boeing 747 cargo plane had just left Bagram Airforce Base when it fell from the sky, killing all those on board.
(WARNING: Graphic footage)
In the video, the cargo plane carrying five military vehicles struggles to maintain power, as it attempts the steep ascent out of the airbase near Kabul. Struggling to remain in the air, the plane shifts from left to right, before it plummets to the ground.
Aviation experts say the steep climb is to avoid insurgent attacks.
"The instruction is to get in quickly and get out so very steep angles going in and a very steep angles going out," said Aviation expert Geoffrey Thomas.
The Taliban claimed responsibility, but that was quickly dismissed by NATO.
NATO's task now is to discover what went wrong. There's many theories of what could have gone wrong.
"There's always the possibility of freight shifting to the back of the airplane ....which could cause a very severe imbalance," said former 747 pilot Ross Aimer.
The cargo plane was owned by National Airlines, which is in a deal with the Pentagon to transport military supplies.
In a statement the company's President expressed his sadness over the loss of the crew.
"This is a devastating loss for our family and we'll work diligently with authorities to find the cause.
"Most importantly, our thoughts and prayers are with our crewmembers and their families."
Brad Hasler was one of the crew who now leaves behind a devastated family.
The 34-year-old got married just two weeks ago, had a 2-year-old daughter and his wife was pregnant with another baby.
(This article has been edited)