Seven American crew members were killed when their 747 cargo plane crashed shortly after taking off from Bagram Air Base in Afghanistan at around 7 a.m. Officials say the National Airlines Boeing 747-400 was on its way to Dubai, United Arab Emirates.

The cause of the crash has yet to be determined. The Aviation Herald and several other websites posted a video of the takeoff taken from a dashboard camera. They posted this account:

"Several observers on the ground reported the National Air Cargo Boeing 747-400 had just lifted off and was climbing through approximately 1200 feet when it's nose sharply rose, the aircraft appeared to have stalled and came down erupting in a blaze... According to a listener on frequency the crew reported the aircraft stalled due to a possible load shift."

Another possible cause is that a sudden gust of wind may have disoriented the 747 plane as it climbed.

National Airlines confirmed in a statement there were no passengers on the 747; the jet was reportedly loaded with military vehicles.

"This was a purely cargo flight and no passengers were aboard," a statement by the company said. "Cargo consisted of vehicles and routine general cargo."

Six of the seven victims were from Michigan, one was from Kentucky. They have now been identified as pilots Brad Hasler of Trenton, Michigan and Jeremy Lipka of Brooklyn, Michigan; First Officers Jamie Brokaw of Monroe , Michigan and Rinku Summan of Canton, Michigan; loadmaster Michael Sheets of Ypsilanti, Michigan, and maintenance crew Gary Stockdale of Romulus, Michigan. Timothy Garrett of Louisville, Ky., was also killed.

National Airlines President Glen Joerger told reporters "This is a devastating loss for our family and we'll work diligently with authorities to find the cause."