1.   One thought it might have been a senior prank.

2.   Coming at the height of senior prank season, from a student known as a bit of a jokester, the warning was shrugged off.

3.   The brain had been swiped last year as a senior prank at a Coffeyville, Kan., high school, Wheeler said.

4.   The plan for a senior prank began about a month ago.

5.   But they are concerned that the senior pranks -- considered rites of passage for thousands of teen-agers -- have intensified well beyond reason.