Lawrence school district leaders used an emergency notification system to call parents about an investigation at Woodlawn School this month.

Monday night, district officials gave board members an update on progress of installation of the SchoolMessenger Notification System, purchased in May after April bomb threats on schools in the county followed the Virginia Tech massacre.

Woodlawn Principal Jeanne Fridell recorded a message Nov. 14 that the system delivered to school parents within about 12 minutes.

The message notified parents of a threatening note found late in the day in a fifth-grade classroom. The school also sent a note home with students the next day.

The calls cost $0.17 per student, but the maximum cap per year for the district is $25,800.

Rick Gammill, the district’s special operations director, said police are still investigating the note and that no one was injured.

The district is still working with SchoolMessenger on implementing a nonemergency part of the system that makes fewer calls per hour.