Damage to Cambridge’s Alewife Station, seen Sunday. (Photo: Marc Levy)

The parking garage at Alewife Station gets a partial reopening Wednesday after an emergency shutdown that followed a car crash last weekend. 

Garage levels G, 2, 3 and 4 will reopen to drivers while the top level – where a driver rammed his car into a concrete wall – will remain closed, T officials said. There also will be no access to the lobby floor. For subway riders, shuttle buses are still replacing red line service between Alewife and Davis stations; the MBTA is working to resume train service this week using the Russell Field headhouse, which is a two-minute walk from the garage.

MBTA Transit Police Supt. Richard Sullivan said Tuesday that the investigation into the crash continues.

“We’re moving at a pace that allows to us be thorough,” Sullivan said. “As soon as we can, we will update when appropriate.”

He said he understands the public’s desire for information about the driver, his motives and what will come next.

What is known now is that just after 1:30 p.m. Saturday, a motorist driving a white car crashed into a concrete barrier of the top floor of the garage, sending that barrier through the mezzanine roof below. The 10,000-pound concrete barrier broke the roof trusses and caused the glass ceiling to shatter.

“It’s just sheer luck that no one was killed,” MBTA Interim General Manager Jeffrey Gonneville said at a press conference Monday. “This could have been an absolutely horrific event.”

In fact, only the driver and a 14-year-old girl on the mezzanine at the time of the crash were hurt. The motorist is hospitalized but not in custody; the young girl sustained only minor injuries.

Sullivan said he’ll continue to update the public as more information comes to light, but more importantly, “we’ll consult and confer with the Middlesex District Attorney’s office.”