TWO RIVERS — A bomb threat at Two Rivers High School led to a letter being sent home to parents today but not to cancellation of school, according to Principal Larry Schlosser.

The threat was found on a wall at the school on Wednesday. It says a bomb will go off Friday if school is not canceled, Schlosser said.

“Clearly, we’re not canceling school,” he said.

Schlosser said he doesn’t know who wrote the threat. The Two Rivers Police Department and school officials are investigating.

The school receives bomb threats “fairly frequently,” Schlosser said. This one was different than others in that it specified a date.

Nonetheless, “we really don’t believe it to be a credible threat,” he said.

The letter asks parents and students to contact the Police Department if they have any information.