When the centurion and those with him who were guarding Jesus saw the earthquake and all that had happened, they were terrified, and exclaimed, "Surely he was the Son of God!" Matthew 27:54
Was it the earthquake that terrified the centurion and his men? Hard to tell. But the combination of the earthquake and Jesus dying had to put a fear into these otherwise brave soldiers.
Was it too late for those men to repent of their ways? No. It's never too late. In fact, you could easily make a case that Jesus had to die first and the earthquake occur before those men would be 'true believers.'
Things happen for a reason all the time, we know that. Seldom, though, do we realize that those things happen for our benefit. I know that it's not about us all the time (as I've stated elsewhere in this space), but occasionally it is.
Take the crucifixion, for example. It was about us.