Hi All
Again, this topic is closed. Speculation may seem good (and most of us tend to do it), however it is not an appropriate topic in this case.
When the official report from the investigation has been released, we may allow the topic to be re-opened (or at least allow an article, or link to, the report to be posted).
Please remember, a number of people were killed in this accident. This can have long reaching effects to family and friends. You never know if someone who knew the person (or knows the family) will read this thread.