The incident took place early Tuesday, March 10, at Hendrick Hudson High School at 2166 Albany Post Road, in Montrose, according to the Westchester County Police.
According to a district notice, building staff reported that the message had been left on the school voice mail system the previous evening.
"The district immediately activated safety protocols, which included placing the high school in a Lockout and Hold in Place, which means that no one was permitted to enter the building and those already inside were instructed to remain in their classrooms," the notice said.
Westchester County Police, New York State Police and the Hendrick Hudson High School Safety Team conducted a thorough safety check of all classrooms and building spaces.
Once it was determined that there was no credible threat, the lockdown was around 9:10 a.m.
Westchester County Police said they continue to investigate the incident.
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