It was a cargo plane, so luckily not many souls aboard.
It had large pallets of cargo, during takeoff they broke free and rolled to the back of the plane, throwing the center of gravity way off, uncorrectably bringing the nose up and causing the stall.
The pilots still managed to get it pretty level, but didn't quite have enough altitude and with a 747 full of fuel the fireball was almost inevitable.
Every job at an airport can be important, this isn't the first heavy brought down by incompetent ramp work.