You would be entirely at fault. How do I know? That accident happened to me when I was 19. The lady even tried to sue me.
I even had 6 witnesses waiting with me when the cops showed up. Didn't matter that she ran the red light, apparently I failed to make sure it was safe to turn left.
There was, however, a milk transport truck that was able to come to a stop in time, so I couldn't even see her lane. She came flying out from beside the milk truck and I clipped her rear driver side.