Who is at fault?

My daughter was involved in an accident in Utah which involved three other drivers.
The accident happened at a intersection which the traffic light had gone out and was flashing red going North and South and flashing yellow going East and West. This intersection is a very besy one with four lanes, a left and right turning lanes going East and West. The North and South lanes are single lanes with both a right and left turning lanes.

It was a little after dusk as my daughter approach the intersection which the light was flashing red in her direction (North). She came to a complete stop and waited for about two or three minutes until the traffic was clear to proceed through the intersection. The lanes of traffic in the westbound direction had stop to let the North and South bound traffic to proceed. Also the traffic in eastbound far right lane had stopped. My daughter then proceeded through the intersection, as did the driver in the southbound lefthand turning lane and the driver going through the intersection in the southbound lane. As she reached almost through the center of the intersection the driver in the open eastbound lane struck the rear-end of my daughter's car. The impact of the hit put my daughter's car into a spin which then hit the driver making the lefthand turn in the southbound turning lane. Her car then struck the other driver coming through the intersection going southbound.

The police where called along with a traffic investagator. Both did not site any driver for fault. This makes it insurance nightmare!
The driver in the southbound lefthand turning lane stated that the driver that struck may daughter failed to slow down and proceed with caution as she approached the intersection. The Utah traffic code states that when there is a flashing yellow light, you must slow down and proceed with caution.

Who is at fault on this one? I feel it was the driver that struck my daughter. I realize that my daughter had the flashing red light, but when you have traffic stopped in both west and east bound lanes to let north and south bound traffic through, what do you do?
The driver that hit my daughter did not slow down or did she try to avoid the accident.

The police report only gives a mark on the drivers who may have caused the accident: My daughter has one; proceeding through the intersection with a flashing red light. The driver who hit my daughter has two; failure to slow down and failure to proceed with caution. Who is at fault?

Thanks