Construction has resumed on one part of the massive Government Center garage redevelopment project in downtown Boston a little over two weeks after a section of the Brutalist-era concrete monolith collapsed during demolition work, killing a crew member.

Contractors have resumed work on the interior fit-out of the 43-story, 1-million-sq-ft One Congress office tower, the future headquarters of hometown financial giant State Street Bank, which stands next to the garage.

The tower is one of the centerpieces of developer HYM Investment Group’s $1.5 billion Bulfinch Crossing mixed-use project, which is taking shape as new building sites are freed up amid a gradual, years-long dismantling of the nearly five-acre, multi-level garage.

Over the weekend, the MBTA resumed Green Line service between North Station and Government Center, which had been suspended after the partial garage collapse. The collapse sent 100 tons of debris tumbling onto the ground and floor above the subway tunnel underneath.

T officials also reopened the Haymarket Station which sits underneath the garage and had suffered damage to its standpipe system during the garage collapse.

The decision to restart service and reopen the Haymarket station came after engineers inspected the tunnels and did not find “any significant issues,” a T spokesperson said in an email.

State transportation officials had previously resumed service on the Orange Line, which also runs beneath the site, several days after the tragedy.

Demolition work on the garage remains in suspension amid an ongoing investigation into the accident that killed 51-year-old operating engineer Peter Monsini of South Easton.

The federal Occupational Safety and Health Administration is probing the collapse as part of a “multi-agency investigation” that includes Boston police, fire and inspectional services department, a spokesperson for the agency stated in an email.

Contractors have been demolishing the 1960s era parking garage in stages since 2017, clearing away sections to make way for an 800-unit residential tower, which opened in 2020, and the new One Congress office tower, slated for completion later this year.

In order to fully move ahead again with its Bulfinch Crossing project, developer HYM will have to secure permission from city, state and federal officials to resume demolition of the garage.

The section that collapsed on March 26 was being taken down piece-by-piece by JDC Demolition to make way for a planned, 410,000-sq-ft life sciences complex. And while work has resumed on the office tower, it, too, will not be able to open for business until the garage demolition work is complete, according to information posted on the website of the Boston Planning and Development Agency.

Meanwhile, local television news channel NBC10 recently reported that firefighters were called to the Government Center garage site on Jan. 14 for an "unsafe, unstable worksite involving a crane," following a water main break by the construction site, the station reported, citing audio of a call picked up on a police scanner.

Fire dept. officials later declared the crane to be stable.

In a statement responding to the NBC10 report, HYM said engineers were brought in to investigate and that the crane was moved in order to make way for a repair crew to dig up and replace sections of the water lines that had caused the flooding.

“All repair work was done by an approved contractor experienced in making such repairs and thoroughly inspected by Boston Water and Sewer (BWSC) before work on the site resumed,” HYM stated.