HINSDALE, Ill. (WLS) -- Hinsdale Central High School was placed on lockdown for a short time Friday afternoon after live ammunition was found on school grounds, Hinsdale police said.
The "shelter-in-place" was prompted by the discovery of a shotgun shell in the school's cafeteria around 11:45 a.m., law enforcement sources told the ABC7 I-Team.
Police said a 15-year-old male student is believed to have brought the ammunition into the school. He was detained early Friday afternoon, but was not found to be in the possession of any weapons. No charges have been filed.
Students were kept in their classrooms as a "precautionary measure" as police canvassed the school Friday afternoon, a District 86 spokesperson said.
The lockdown was lifted around 1:45 p.m. Friday. No one was injured.