Hulking Government Center Garage in downtown Boston to come down this summer

Congress Street beneath the garage will be closed through Labor Day to allow for demolition work that will make way for a large redevelopment.

Demolition work will resume next on the Government Center Garage — pictured here in 2016 — with Congress Street set to close through Labor Day while the massive structure is taken down.Jonathan Wiggs

Crews are preparing to resume work demolishing the Government Center Garage, which has been halted since a fatal collapse in late March, and will soon close the busy street below for the rest of the summer.

Beginning July 11, Congress Street from New Chardon Street to Sudbury Street will be closed to traffic, the city said Tuesday, with detours for vehicles, bicycles, and pedestrians. Construction crews hope to finish the phase of work that requires shutting down the street underneath the massive concrete structure, where Merrimac Street changes to Congress Street, by Labor Day.

Taking down a portion of the Government Center Garage over the busy roadway is the key next step to The HYM Investment Group’s multi-billion-dollar Bulfinch Crossing mixed-use development. Residential tower The Sudbury has already opened, while interior work continues at One Congress, the $1.3 billion office tower that will be the headquarters of State Street Corp., InterSystems, and K&L Gates when complete. Both those buildings are built around and on top of a portion of the garage which will stay. The rest — over Congress Street and the former Haymarket bus depot — will come down to make way for a 410,000-square-foot laboratory building.

The March collapse and last month’s multi-day shutdown of the Green and Orange Lines below have raised safety concerns, but the street closure is “part of scheduled work,” HYM said in a statement Tuesday. The developer, along with its Washington, D.C.-based financial partner National Real Estate Advisors, general contractor John Moriarty and Associates, and other project partners “have been and continue to be in coordination and communication with all critical state, city, local and transit entities and officials,” HYM said.

“The resumption of work on the Government Center Garage is being conducted with the utmost adherence to stringent industry protocol, ensuring that the safety of our workers and the public is prioritized at all times,” the developer said.

When Congress Street closes, Sudbury Street “will be re-configured from a one-way street to a two-way street,” HYM said, while the MBTA’s Haymarket Station will remain open for bus and train service.

A portion of the Government Center Garage collapsed on Saturday, March 26 around 5:30 p.m., when 51-year-old Peter Monsini of Easton was operating a piece of heavy equipment and fell nine stories to his death when the garage floor buckled beneath him.

Commuters leave the Haymarket T station, which will remain open while demolition resumes on the Government Center Garage above.David L. Ryan/Globe Staff

Inspectors began an investigation into Monsini’s death as well as the structural integrity of the garage. That led to the abrupt closure of the MBTA Green and Orange Lines on June 23, as investigators discovered a support column near Haymarket Station that had been deteriorated by what appeared to be decades of water damage. Crews fortified the damaged column with steel bracing, and by Sunday, June 26, officials had deemed the tunnels safe enough for Orange and Green Line trains to resume service.

A representative from the federal workplace safety organization OSHA said its investigation into the garage collapse is ongoing.

“OSHA’s investigation continues and OSHA does not discuss the specifics of ongoing investigations,” an OSHA representative said by email.

— Information from prior Globe reports was used in this story.