Who is at fault when hit on the passenger side when making a left hand turn?

This question is very broad. More specifics are needed to determine fault. Who was turning left? Were you at a light, if so did you have a green turn arrow or light? Who had the right of way. Were there cars behind you, in front of you? What was your speed? Were there witnesses? Were the police called, is there a report? Were you cited or ticketed?