More than 2,500 Lake Mary High School students were absent from school Monday after a shooting threat was left on a bathroom stall last week.

Only 388 students were present for school Monday — or just 15 percent of the student population of almost 3,000.

A student parking lot normally filled to capacity with vehicles was nearly empty. Inside the school, a cafeteria was mostly empty for breakfast Monday morning, and many hallways were vacant as the few kids who did attend made their way to class.

School officials were alerted four days ago about the threatening message, found on a boys bathroom stall. They don't think the threat is legitimate, but they gave permission for students to stay home with parental permission. School officials said students must provide a note from their parents if they did not come to school Monday morning.

"There is no real scenario to prevent these types of things other than having stern consequences for those individuals once they're caught for the disruption that they are causing," said Michael Lawrence of Seminole County Schools. "They are not only causing a school disruption among students and families and staff but also added resources from law enforcement."

The Seminole County Sheriff's Office increased patrols on and around campus.