CPR to man at Christmas Market 12/12

My father collapsed near the Christmas Market at Civic Center Plaza or somewhere nearby yesterday. He was taken to the hospital by ambulance where he passed away. We only learned about it today and are trying to put together the pieces of what happened/ where it happened and who was with him. If anyone has any information please message or dm. I heard someone gave him cpr until the ambulance came and I’d like to hear more about what happened.