SOUTH BEND, Ind. — The parents of a University of Notre Dame freshman severely injured in a 2019 fall in a campus dormitory during a party filed a lawsuit Tuesday against the school, which they claim condoned a “quasi-fraternity atmosphere” at an on-campus residence hall.The lawsuit filed in St. Joseph County, Ind., by Stephen and Debbie Tennant of Gurnee, Ill., claims the university put their son, Sean, 20, at risk. Sean Tennant, who was 18 at the time, survived the 30-foot fall on a stairwell in Sorin …