HARTLAND -- A hand-written note found in North Shore Middle School in Hartland prompted school officials to evacuate the building on Monday, May 8th.
Officials say 375 students were evacuated from the building -- and bomb-sniffing dogs from Milwaukee were brought in to check the building.
Investigators would not say what was written on the note. But per protocol, all threats are taken seriously.
"We treat them all very serious. The type of response you saw with multiple police and multiple fire units is what you're going to have. You're going to have the evacuation. You're going to have the search of the building, bomb-sniffing dogs to ensure the safety of the children," Michael Bagin, Hartland police chief said.
Officials gave the "all clear" on the middle school around 4:40 p.m.
Monitor FOX6 News and FOX6Now.com for updates on this developing story.