( CNN ) -- A building under construction in downtown Boston partially collapsed Thursday morning , sending two people to the hospital , the city 's fire department said . The incident happened about 8 a.m. at a construction site at 45 Stuart St. , the Boston Fire Department tweeted . The collapse occurred on the 12th floor of what 's slated to be a 33-story residential high-rise , causing damage from the 11th floor 's roof down to the fifth floor . First responders treated two people with injuries that were not life-threatening and then took them to nearby Tufts Medical Center . The fire department later explained that one of those had `` a serious head injury , '' while the other had a minor injury . `` No others workers reported trapped at this time , '' the fire department tweeted . According to a sign posted outside the site , near the city 's Chinatown district and around the corner from Boston Common , the building was slated to be completed in the middle of next year .
NEW : Fire department says 1 person suffers `` serious head injury '' ; another has minor injury . 33-story residential high-rise was under construction in downtown Boston . Score: 6