A message came through the Safe2Say system Wednesday night, threatening the "health safety and welfare of students and staff."
Despite working throughout Wednesday night, South Whitehall Township police couldn't pinpoint the origin, which forced the school district to close Orefield Middle School.
An email from Superintendent Dr. Mark Madson explained that because the school bus parking garage is near the middle school, the district wouldn't be able to provide transportation. Therefore, all schools in the district closed Thursday.
School officials confirmed schools will still be closed on Friday, with classes going virtual.
In an email Thursday night, the superintendent said, "This is a frustrating time for everyone. We will continue to work with law enforcement to make the best decision for the safety of our school community."
The FBI, Pennsylvania State Police and Upper Macungie Police Department are assisting South Whitehall Township police in the investigation.