Without wanting to make anyone feel bad. People have died in this tragedy,please just let it be. None of us know what it was like to be there. And more importantly none of us know what caused it.
Every time an event such as this happens (far to frequently of late) the wringing of hands and speculation that goes on here I find quite frustrating.
Time will tell us what happened in the meantime spare a thought not only for the dead and their families but also for the people who were there and witnessed this awful accident, they will have this in their heads for the rest of their lives.