41 Park Row also houses the Haskins Laboratories, 2,700 square feet (250 m2) of Dr. Seymour H. Hutner,[17] where medical experiments are held, like the Green tea extract study in the international media.[34] The buildings of 157 William Street, 161 William Street, and 163 William Street were acquired by Pace following the September 11 attacks to make up for loss of the entire 55th floor, 45,943 square feet (4,268.2 m2), in the North Tower of the World Trade Center which used to house Pace University's World Trade Institute and World Trade Conference Center (See the section below entitled September 11, 2001). The Willam Street buildings house classrooms, offices of the Seidenberg School of Computer Science & Information Systems, the School of Education, the College of Health Professions, the university's business incubators, along with Pace's Downtown Conference Center[35] where the e.MBA residency sessions are held (Pace also has leased office space in 156 William Street). Pace has residence halls at 182 Broadway and 33 Beekman Street.