Authorities say an upset Husker fan crossed the line by threatening the life of a Nebraska football coach.

Sean Callahan with  says the threat was found on a telephone answering machine. “Police are investigating a death threat left on defensive coordinator’s Kevin Cosgrove’s over an answering machine in his office. The death threats were left following Nebraska’s loss against Kansas,” he says.

Callahan says Cosgrove has received threats before. “A couple years ago, there was a similar situation that happened with the Cosgroves. It didn’t get as much press at the time, but I know something like this has happened before where the family had to go though something similar to this.”

University of Nebraska police have traced the call but have yet to make an arrest.