Officials say a worker digging a trench on a New Jersey college campus unearthed an old explosive device that apparently was used in construction.

Montclair State University
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A portion of the Montclair State University campus in Little Falls will remain closed Thursday. However, no classes have been canceled.

Passaic County Sheriff Richard Berdnik says the bomb squad stopped working on the device on Wednesday night because of darkness. Berdnik says officers are trying to determine how it got there and disarm it.

Montclair State officials tell The Record newspaper the area had been a quarry decades ago and there's a potential for leftover blasting caps in the area.

(Copyright 2012 by The Associated Press. All Rights Reserved.)

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