ADDISON, Ill. (CBS) – A tense lockdown last week at an Addison middle school was caused by a hoax, officials said Monday.

School officials found a female student at Indian Trail Junior High School “restrained” in a restroom Friday morning, prompting police to sweep the building and a nearby elementary school for an intruder.  Students were released in the afternoon.

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On Monday, Addison police said they determined after an investigation that there was no danger.

“During the course of the investigation, the student admitted fabricating the story,” Addison Police Director Timothy “Bill” Hayden said during a Monday news conference. “At no time was security at Indian Train Junior High School breached.”

Police officials declined to offer details. They said the incident demonstrated that authorities acted quickly with school officials to ensure the safety of students and staff members.

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“It was a positive outcome to an unfortunate circumstance,” Hayden said.

District 4 Supt. John Langton wouldn’t speculate what kind of punishment the student faces for fabricating the story. School officials would review the district’s policies and laws, he said.

“That’s something that’s going to be worked through with that child’s family,” he said.

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Some parents criticized the way District 4 officials handled the lockdown, but school officials said they followed proper protocol to ensure students’ safety.