Superintendent Christopher Borsari said the decision for the lockdown was made Monday morning after a Sleepy Hollow High School teacher received a threatening email message.
The message was shared with the Sleepy Hollow Police who followed up with the Westchester County Intel Center and the Westchester County Police, Borsari said.
"Although the threat is considered to be non-credible, as it has been received by numerous school districts throughout the country, out of precaution, we have placed all district schools on Lockout until the end of the school day," he said in a statement.
Lockout is an emergency procedure where all normal activities occur within the school buildings. Recess and other outside activities will be conducted inside.
"At this time we plan to have a normal afternoon dismissal and all afterschool activities will occur as scheduled," he added.
Sleepy Hollow Police are making extra stops at the school throughout the day.
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