UPDATE: The lockdown at Grain Valley High School ended around 11 a.m. Thursday.
Grain Valley Schools posted on its Facebook page that local officers led an investigation into an email threat at Grain Valley High School.
Grain Valley police and a K-9 unit from Kansas City police conducted a sweep through the school, and the treat was determined to not be credible.
Grain Valley High School is no longer in lockdown. The Grain Valley Police Department led an investigation into an email...
Posted by Grain Valley Schools on Thursday, December 17, 2015
Grain Valley High School tweeted the students were safe in lockdown while law enforcement agencies conducted a sweep of the school.