I understand your point, but maybe these people were just choosing the less painful death, in their minds. Or maybe they thought jumping would be their only chance at survival - or prolong life for a few more moments and allow them to take a few last breaths of air. We can't understand why they did this, but I don't think it was because of a lack of faith in God. God does not guarantee our safety, but he does guarantee He will be with us if we ask.
Thank you for a considerate, polite and understanding reply. I agree with what you say, and I don't pretend to know what was going on in their heart and head at that time, I just know what I hope would be in my heart and head if I were there.