Seems to be an uncontained fire in the cargo holds. Without knowing the exact cause of the fire yet, for me it is reason enough to ban lithium ion batteries from ever being carried in the holds of any aircraft. They are unstable and extremely difficult to extinguish and are beyond the cargo fire suppression capabilities of commercial aircraft.
Have a look at the toxic cocktail they were carrying. Aircraft fires can develop so quickly that even with an emergency descent to sea level the aircraft can become uncontrollable.
This, the Swiss Air MD11 off Nova Scotia and the recent DHL 747 crash are all pilots worst nightmares.
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Nail penetration testLaptop fire move to 2 min mark if you cant wait.
There are many cases of Lipo and Lion batteries becoming unstable and causing havoc. Many are due to charging issues but there are many that just happen spontaneously. HP laptop batteries are a case in point.