Pranksters placed a yellow quarantine sign outside the Central school building in Waterloo, Iowa:
The quarantine signal was placed in the most conspicuous place on the building. The lads who are responsible for the misdemeanor probably thought it would be a great joke and possibly be the means of permitting them to a holiday...
The teachers and high school scholars entered the building at the main entrance, but did not go into the room just back of the sign until assured that there was no danger. It was only a short time until the news that the west side Central building was quarantined spread pretty well over the town and Mr. Hukill and Mrs. Couch, who use the high school room, were kept busy denying the report and explaining.
[Waterloo Daily Courier]