Scott Olson, Getty Images
A member of campus security stands guard Monday at one of the entrances to St. Xavier University in Chicago.

CHICAGO — A message scrawled in a university bathroom — "Be prepared to die on 4/14" — left not just the college's campus empty Monday but also those of two adjoining high schools and a pair of nearby elementary schools.

After the precautions were taken at St. Xavier University on the city's southwest side, Malcolm X College evacuated students and canceled daytime classes Monday after a similar threat was found in a bathroom at the campus west of downtown. And Michigan's Oakland University was closed Monday because of threatening graffiti mentioning April 14.

The closures, two days before the anniversary of the Virginia Tech killings and two months after the deadly rampage at Northern Illinois University, illustrate the challenge such threats pose to school administrators, who have to decide just how seriously to take them.

"I can see why they're doing it for the safety of the kids. But I see it as over the top," said Lynn Ruggiero, whose daughter is a freshman at one of the high schools that shares a campus with Xavier and closed Monday.

Ruggiero said she figures whoever wrote the threat "is getting a certain satisfaction" from putting thousands of Chicago students out of class. Still, she knows school officials have a hard time pleasing everyone.

"If they hadn't closed, people would have said, 'How come you didn't?"'

St. Xavier and Malcolm X are about 15 miles apart, and despite the fact that the threats had similar wording, there was no indication they were related, Chicago police spokeswoman Monique Bond said. The graffiti at St. Xavier was widely publicized over the weekend and also contained in updates the college placed on its Web site.

While St. Xavier decided Friday to close until further notice, classes at Malcolm X resumed late Monday afternoon after bomb-sniffing dogs swept the campus.

Oakland University, an 18,000-student state school about 20 miles north of Detroit, planned to resume classes today. The graffiti that prompted its shutdown also made a reference to "4/14" but didn't specify a type or time of an attack, university spokesman Ted Montgomery said.

School administrators' decisions about handling threats can be made easier by having a plan in place should a crisis arise, said Larry Consalvos, senior vice president at iXP Corp., a security consulting firm which works with universities on campus safety. Knowing how they'll deal with the chain of command, first responders, communication and alarm systems is vital, Consalvos said, and allows administrators to decide when to monitor a situation and when to shut down a campus.

"I don't think you can be cavalier about the seriousness of any threat," Consalvos said.

In the Chicago area, two elementary schools and two high schools near St. Xavier decided to cancel classes Monday after a Saturday morning meeting between school officials and city police. The fact that the threat mentioned a certain date helped administrators at Evergreen Park Southwest Elementary decide to shut down, district superintendent Craig Fiegel said. Other schools in the district canceled outdoor recess and PE classes Monday.

Fiegel called such violent graffiti "the new bomb threat," remembering a time in the 1960s when bomb threats were regularly used to close down institutions. And he said he worries that the closures could encourage other people who get a kick out of causing chaos.

"At what point is it serious and at what point do you have to go on with it?" Fiegel said.

Edelena Lee was one of a number of students arriving for class Monday afternoon at Malcolm X who had not heard of the threat, or that the school had been locked down. Despite disappointment that she may have wasted a trip to campus, she had no problem with the decision to close the school, particularly so soon after a gunman opened fire and killed five students and himself in February at NIU, about 65 miles west of Chicago.

"I think people have issues nowadays," said Lee, 30. "You can never be too cautious."