Montgomery County lawmakers have asked for regular briefings on the state of the troubled Silver Spring Transit Center.

The briefings by County Executive Ike Leggett or his staff should "focus on the county's plan to get a safe and reliable transit center open to the public as quickly as possible," County Council President Nancy Navarro, D-Eastern County, and Council Transportation, Infrastructure, Energy and Environment Committee Chairman Roger Berliner, D-Bethesda, wrote in a memo Monday.

However, the briefings will not address who is responsible financially for the delays or the repairs, which may be the subject of an impending lawsuit, they wrote.

The request follows a recent report by a county-commissioned engineering firm that the three-story structure in downtown Silver Spring has significant design and construction defects that could cause buses to fall through thin concrete floors, potentially killing the commuters below. The county and general contractor Foulger-Pratt are in the process of working out a solution.

The $124 million structure was originally scheduled to open in 2011 and is supposed to offer access to Metrorail, MARC and Purple Line light rail trains, as well as Metro, Ride On and Maryland Transit Administration commuter buses. However, Metro has said it may not accept ownership of the structure as planned if the problems -- excessive cracking, inadequate reinforcing steel and concrete that is too weak and too thin -- are not fixed.

The delays have cost the county $2.2 million, which county officials say they expect Foulger-Pratt to pay. Firm principal Bryant Foulger has denied fault, saying it was the county's job to ensure the structure was safe.