Powder Puff Hazing incident

Pardon me if this question has been addressed on one of the other boards. My question is about the hazing incident that happened recently among a group of high school girls (and a few boys) after a game of powder puff football in Northbrook, Illinois.

By what authority can the high school administration expell the students involved in the hazing? The incident was not at a school sponsored event, it did not happen on school property (it occurred at a Cook County park), nor did it happen during school hours.

An AP story says, “Although the event was off-campus and not sanctioned by the school, officials have said state and local school codes allow the 10-day suspensions.”

Anyone know the details about these state and local school codes?

The kids had a code of conduct, inplied or signed, that covered off school grounds events.

Additional Background:

Source: http://www.cnn.com/2003/EDUCATION/05/20/highschool.hazing.ap/index.html

Source: http://story.news.yahoo.com/news?tmpl=story&u=/ap/20030521/ap_on_re_us/high_school_hazing_5

Glenbrook statements and press releases related to the hazing incident