So, in the Oklahoma case, was He just or merciful?
Perhaps He was both just and merciful. I think that in heaven right now there is mourning over the many lives lost and rejoicing over glorious homecomings.
We see so little of the whole of reality that we sometime become like the toddler asking incessant "Why, Mommy?" questions. And, like that toddler, we're never satisfied by the answers.
Maybe the best answer for now is: God is sovereign; trust Him.
But that's hard. Very hard.