Here is the original item:
Since the roof of Orlando Hall leaks, students know to check their seats.
To avoid soaking their pants in a puddle of water and then sitting in damp
underwear for an entire class.
You chose to connect the infinitive phrase to the main clause in front, like this:
Since the roof of Orlando Hall leaks, students know to check their
seats;
to avoid soaking their pants in a puddle of water and then sitting
in damp underwear for an entire class.
Unfortunately, you cannot connect these two parts with a semicolon. Review the rules.