As others have said, this video has been commented for its authenticity elsewhere online – captured ‘right place right time’; don’t forget that dashboard mounted cameras are common elsewhere in the world (cf the recent meteor captured in Russia by multiple dashboard cameras).
As others have mentioned, the plane (albeit a 747) was effectively a military transport aircraft, and cargo military aircraft getting into accidents or incidents tend to be heavily underreported.
Initial speculation (its cargo apparently was 5 vehicles) was that there was a cargo move on climb out and that this caused the problems you tragically saw.
A sad, tragic incident. May they rest in peace.