The president of Grinnell College has told students they must leave the campus by March 23 to help halt the spread of the new coronavirus disease. Classes will continue to meet through Friday, the last day before spring break. A Tuesday letter from President Raynard Kington says that after March 30 the college will shift to online classes for the rest of the semester. The college will cancel all athletic events, including practices, for the rest of the semester. Kington also says the college might cancel May’s commencement ceremony and other large events.