Guys
People died here, so lets remember this.
I have probably 15,000 hours flying 747s over 19 years and I wouldn't speculate or pontificate on the causes of this tragic accident on a forum like this.
I have my personal views on what caused the accident, and I certainly wouldn't publicly air them: there is nothing to be gained from this.
Thankfully there is a video that will help the NTSB, but in the meantime please let's have some decorum and respect our deceased professionals and their families.