MARION — About 60 Excelsior Middle School students stayed home from school Friday, after a rumor spread earlier this week that a student was threatening violence.The school of almost 1,000 sixth-, seventh- and eighth-graders had 6 percent of students “called out by their parents as a result of the rumor,” Linn-Mar Community School District spokesman Kevin Fry said.The rumor was unfounded, and there were no incidents Friday, said Officer Tom Daubs, a school resource officer for the Linn-Mar district.“I 100 percent confirmed it was a miscommunication,” Daubs said.