This is a question that many people ask when tragedy comes, either personal or public. God is a loving God. For the Christian, God allows sorry and heartbreak into our lives to draw us closer to Him. For the unsaved., He is giving them an opportunity to seek Him for salvation and comfort. Do we understand? No! However, with the passage of time we see blessing. Hearing the testimonies of people who have overcome great tragedies in their lives helps us to get through the hard times. If you are facing trials it is the time to draw close to God. He will be with you in every circumstance.
1 Peter 5:7
Casting all your care upon him; for he careth for you.
Center for Evangelists 