(Wabasha, MN) — The principal of Hayfield High School in southeastern Minnesota is jailed for the alleged sexual assault of students between 1997 and 2003 when he was a teen. Wabasha County authorities say 37-year-old Grant Klennert is charged with first- and second-degree criminal sexual conduct. Deputies began investigating Klennert in October after an alleged victim claimed that he began sexually assaulting her in second grade. A second person told law enforcement they were sexually assaulted by him at age 14 and a third alleged victim was seven. The school has placed Klennert on administrative leave.