From an AP story:

Salt Lake City (AP) — The FBI says an American Airlines plane headed to St. Louis was diverted to Salt Lake City today after a suspicious note was found on board.

The plane was traveling from Portland to St. Louis when a child found a note in the armrest. The note said there was a bomb on the plane. The note appeared to be in a child’s handwriting. The word “bomb” was misspelled as “boom.”

They’ll probably find the child in question and zero-tolerance him into prison, of course.