This is an archived article that was published on sltrib.com in 2013, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

As an improvised explosive devices go, the backpack found abandoned at a Spanish Fork charter school complex didn't add up. But it did contain a calculator.

Spanish Fork police Lt. Matt Johnson said Tuesday that the backpack, found outside an entry door of the American Leadership Academy at 898 W. 1100 South about 9:30 a.m. Monday, did look suspicious: it was, for example, wrapped with duct tape.

Maybe, it was just old and falling apart. But in an age of terrorism targeting so-called "soft targets" like public gathering places and particularly schools, police took no chances. All 1,600 students and staff were evacuated from the campus, which includes elementary, middle and high schools.

Spanish Fork police and fire crews and the Utah County Sheriff's office bomb squad responded. As parents picked up their children at a nearby sports park, a robot removed the backpack, placed it in a "bomb bucket" and then the item was taken to a remote location in a nearby canyon.

"When they X-rayed the backpack, it showed electrical components. But when they detonated it, they found all that was inside were some books, deodorant — and a calculator," Johnson said.

While those items did not add up to a bomb, it remained unknown whether the person who left the backpack intended it to appear to be one. No bomb threats to the school were reported to have been made prior to the incident.

That continued to be under investigation, and police will be reviewing on-site security camera video to see if they can identify the person who placed, or forgot the backpack where it was found on Monday.

Twitter: @remims