A "suspicious" device that triggered a soft lockdown of Prospect High School on Wednesday morning was later determined to be part of a classroom extra-credit science experiment, authorities said.
The device was discovered about 9:30 a.m. on the east side of campus outside the school, 801 W. Kensington Road in Mount Prospect. School officials said they contacted police and decided to initiate a soft lockdown as a precaution.
Authorities with the Cook County Bomb Squad later determined the device was safe and posed no threat.
"Apparently this was extra credit for class," said Venetia Miles, spokeswoman for Northwest Suburban High School District 214. "Several students decided they would do the extra credit. My understanding is the students were outside and I don't think they intended to leave the device on the ground, but they got busy doing something and may have picked up their backpacks and forgot about it."
Police found a similar device in a vehicle in the school parking lot, and the device "provided key indicators it did not pose a threat to the school community or the students," authorities said in a news release. Police later spoke with the car's owner who said it was part of an extra-credit assignment.
During the soft lockdown, students and staff were asked to remain in the school building, but could continue with their normal activities. Exterior doors were locked, not allowing anyone to enter the school, Miles said. The lockdown was lifted by 10:20 a.m.