MADISON, Wis. -- The city of Madison and the state of Wisconsin are looking to intervene in a lawsuit over the Brittany Zimmermann 911 call and investigation reports.

A group of media outlets filed the lawsuit against Dane County. The media group, which includes WISC-TV, is seeking the release of the 911 call and the complete investigation into how it was handled.

An internal investigation found that the 911 call from Zimmermann when she was being attacked in April lasted 57 seconds, but the operator wasn't able to hear "sounds possibly indicating an emergency."

Records showed the 911 operator did not call back to the number to determine if there was an emergency, and no officers were dispatched to the area where the cell phone call originated until 48 minutes later, after a roommate found the 21-year-old Zimmermann dead.

The stabbing death of the University of Wisconsin-Madison student from Marshfield remains unsolved.

Dane County 911 center officials said in their May 6 report that the operator could not hear screams and sounds of a struggle. A police detective is quoted in a search warrant document as saying the 911 call had those sounds.

On Friday, the city and state asked for a closed hearing so they can play the tape. Both argued that the release of the tape will hurt the investigation.

The state said it believes that playing the call will also victimize the Zimmermann family and "every person that has ever lost a loved one or friend by homicide."