FLINT, Mich. (AP) - Classes have been canceled for the day at Kettering University as officials investigate racist graffiti at a residence hall at the Michigan school. The Flint Journal reports letters sent to staff, faculty, and students note at least two recent cases of racist and profane graffiti at Thompson Hall on the school's Flint campus. The school says the graffiti reported Thursday and Sunday was immediately removed. Classes were canceled Tuesday. The school's President Robert McMahan says in a letter that he's "deeply upset by these incidents, for the pain this has caused the students to whom these messages were directed, and for the hurt this has caused to our entire campus community." WEYI-TV reports black students were targeted by the graffiti. Local and federal law enforcement officials are investigating.