7th graders got a really lesson in school.

It was just an ordinary day with a substitute teacher for the 7th graders in Dearborn schools when the unexpected happened! The substitute loaded up and started to play, what he thought was an educational film, the kids got a bigger lesson then they could have ever imagined. It was not an educational film about history, but a pornographic film flashed on the screen.

School officials explained to the Detroit Free Press what happened in that 7th grade class room...

The teacher was attempting to play a video of Lewis and Clark for a U.S. history class on March 13 when the X-rated video showed on the screen instead.

No one is sure how the pornographic film got through the filtering system the school has in place, but they do know it was not a prank on the teacher. According to Dearborn School Communication Director Dave Mustonen...

A personnel investigation by Dearborn police and the school district was complete. However a separate investigation is ongoing by the district's information technology department.

Yet, even through the teacher was not found guilty of internally showing the film to students The Detroit Free Press is reporting that...

The school district decided not to rehire the substitute teacher because there's no confirmation of the video's origin. Dearborn police found "no criminal intent." The substitute was hired under a contract through a substitute teacher service, allowing the district to individually select substitutes.

This is a sticky situation for everyone involved, there are no winners in this case.