I'm not sure if everyone's time is determined by God to die. I do believe He knows when, where and how everyone will die but I'm not sure if he determines the actual time and method.
I agree with Stella. God knows everything, but it doesn't mean that He always determines when and how everybody will die. He may some times
**, but not all the time. He gives us free will. Our good and bad choices sometimes affect multitudes and generations to come, in a good or in a bad way. In His infinite wisdom, God intervenes whichever way He wants to, to the extent that He wants to and as much or as little as he wants to intervene.
Who is to say that instead of 30+ victims in this shooting, there were really going to be 60+ had God not intervened? Who knows?
**1 Samuel 28:18-19"Because you did not obey the LORD or carry out his fierce wrath against the Amalekites, the LORD has done this to you today. The LORD will hand over both Israel and you to the Philistines, and
tomorrow you and your sons will be with me."