 MIT has an active Greek and co-op housing system, including thirty-six fraternities, sororities, and independent living groups (FSILGs). As of 2015, 98 % of all undergraduates lived in MIT-affiliated housing; 54 % of the men participated in fraternities and 20 % of the women were involved in sororities. Most FSILGs are located across the river in Back Bay near where MIT was founded, and there is also a cluster of fraternities on MIT's West Campus that face the Charles River Basin. After the 1997 alcohol-related death of Scott Krueger, a new pledge at the Phi Gamma Delta fraternity, MIT required all freshmen to live in the dormitory system starting in 2002. Because FSILGs had previously housed as many as 300 freshmen off-campus, the new policy could not be implemented until Simmons Hall opened in that year.
