Police say there is no threat to the public tonight, as a search in and around Kiel High School has not yet turned up signs of shots fired.
"We have a staff member who reported hearing what she believed was a gunshot," Kiel Police Chief Dave Funkhouser said.
The staff member, who police say is an experienced hunter, called police just before 7 this morning.
"She did exactly what we wanted her to do," Funkhouser said.
The school quickly went into lockdown, and the district rerouted students on buses away from the high school. Officers then went room by room looking for evidence. They have not found signs of a gun or a shooter.
"It could have been fireworks, it could have been a gunshot, it could have been any number of different things," Funkhouser said. "We are working and checking through those layers of possibility. We certainly take everything as serious as possible."
Police said it could also be related to threats made earlier in the week. Tuesday, police got word of a school shooting planned for Friday. District leaders said they increased their police presence in schools.
"Tried to alert parents and be very clear that we had no credible evidence of a threat, and that we were working seamlessly with our police department," Superintendent Brad Ebert said.
Police said nobody is in custody, and there are no suspects. There are also no injuries.
"Everything went as planned, as well as it could of," Funkhouser said. "I'm very proud of the way our school district responded to this."
All schools in the district closed Friday. District leaders said they are planning to bring students back to school for Monday classes.