MARANA, Ariz. (NBC, KYMA) - Classes were cancelled at an Arizona high school Tuesday due to a death investigation. Police responded to Marana High School just before 7 a.m. after reports of a body being discovered on campus. Preliminary information indicates a person broke into the school at about 1:30 a.m. before staff members located the body later in the morning. The Marana Police Department said the person has been identified as a Marana Hig…