An upper floor of the apartment building under construction behind Jacob Wirth on Stuart Street collapsed and fell several floors around 7:50 a.m.
One worker was trapped by steel beams and rebar on the fifth floor of 45 Stuart St. The Boston Fire Department extricated him, reports he suffered a serious head injury. A second worker suffered minor injuries.
Firefighters report two structural beams on the fifth floor show signs of major damage.
Stuart, Washington and Tremont streets were shut. OSHA is on the way.
The AVA Theater District is a $175-million, 398-unit project.