Heavenly Father,Holy is your name.  I come in heartfelt prayer for all those victims  and their  circle of family and friends who are grieving. This is a tragic , horrific thing that has happened. Lord I pray that a mighty move of love and comfort will be encamped around each hurting heart.   
They're hurting for many reasons, and I ask You to help them through this season of loss.  I reach out to You, Shepard of compassion and the source of every comfort, asking you to touch them with Your unfailing love and kindness. Jesus  comfort them as they're going through their struggles, and bring them through the tough things ahead. Come alongside them in their pain, and strengthen them so they'll one day be able to help others who face the same struggles.
Lord I pray for your wings of comfort are  close to people whose hearts are breaking, those who are discouraged and have given up hope or stricken with great fear. May You Christ Jesus see their troubles and grief and respond when they cry out. Your compassion stretches the heavens for us when we are in need.
When they're hurting, help them find their joy in You, for it's Your joy that will be their strength. Help them to trust You as their God of hope. Fill them with Your joy, peace, and hope by the power of the Holy Spirit. Help them experience the love, joy, and peace that are the results of His life in them, no matter what they're going through. Lord just knowing you are there is a cause of hope a better day and season. Lord I lift up prayer to my brothers and sisters that are grieving and so many others prayers worldwide are being lifted up in you name Jesus.
May they sense Your presence in this hour of need. Pour out a double portion of healing and comfort that they may lift their eyes and know that help has come.  In Jesus Christ , Yeshua's name I pray amen.

Psalm 43:3 O send out thy light and thy truth: let them lead me; let them bring me unto thy holy hill, and to thy tabernacles.

Lord when we are weak, your are our strength. When there is darkness, your our light and when we are filled with grief, your presence comforts us. Lord dwell with the broken hearted and carry them when their strength is weary. Thank you for your loving kindness O Shepard. In Jesus Christ, Yeshau's name I pray amen.