Northwest Elementary School was on a precautionary lock down for about 50 minutes beginning at about 10:45 a.m. today.

Mike Strutt, Butler School District superintendent, said the lock down was on a request from the state police related to an activity in the neighborhood. No students were ever in harm's way, Strutt said.

“There was no imminent danger,” Strutt said. “It was just a precaution.”

In this case, the lock down simply prevented people from entering or leaving the building. The school's 400 students, in kindergarten through grade 6, continued activities inside the building normally.

State police have released no information about the incident that preceded the lock down.