Update: 10:55 a.m. Man now in custody, being brought to a hospital for observation.
Update, 9:10 a.m. Stuart Street remains shut.
The person is on the 14th floor, which Emerson College rented to house students this year, but the campus newspaper reports he's not an Emerson student.
Police have been on scene since shortly after 4:30 p.m. The man has been busy disassembling the room and throwing things out the room's windows, including a mattress, a wall-mounted TV, chairs and the glass parts of the windows themselves. He smashed some items with a machete or large knife.