What did mike and crash do in the cafeteria their first day of middle school crash book?

In the book "Crash" by Jerry Spinelli, Mike and Crash got into a fight in the cafeteria on their first day of middle school. Crash was being his usual trouble-making self, and Mike, who had always been his friend, finally stood up to him. This led to a physical altercation that caught the attention of everyone in the cafeteria.