BOSTON — The Community Builders (TCB) and the Boston Housing Authority (BHA) have broken ground on the redevelopment of the Mildred C. Hailey Apartments in the state capital’s Jackson Square neighborhood. The project will replace 253 existing units with two six-story buildings that will house 223 units that will be subject to a range of income restrictions. Another 516 units will remain in the public housing program under BHA ownership. The project also includes the construction of a 6,800-square-foot community center and 1,520 square feet of commercial space. A timeline for completion was not disclosed.