WASHINGTON — Transportation secretary Pete Buttigieg on Wednesday said it was unclear that any bridge in existence could have withstood the impact of a modern freighter that the Francis Scott Key Bridge in Baltimore suffered earlier this week, which demolished the structure and shuttered the city’s port.

“It’s not just big as a building, it’s really as big as a block,” said Buttigieg, appearing on the podium with Coast Guard Vice Admiral Peter Gautier for the White House’s daily press briefing. “A bridge like this one, completed in the 1970s, was simply not made to withstand a direct impact on a critical support pier from a vessel that weighs about 200 million pounds, orders of magnitude bigger than cargo ships that were in service in that region at the time that bridge was first built.”

A Singapore-flagged container ship lost power Tuesday and struck a key structural component of the bridge, sending it tumbling into the Patapsco River where it enters Chesapeake Bay. Six highway maintenance workers on the bridge at the time are believed to have died in the accident.

Buttigieg said state and federal authorities are currently working to clear the debris, move the 984-foot Dali — out of the way and reopen the channel so ships can resume traveling in and out of Baltimore, the fifth busiest port on the East Coast. Neither he nor Gautier would provide a ballpark estimate of when that could be.

Officials are also investigating the bridge’s collapse, both to understand why the portions that came down failed and assess the condition of the sections that remain standing, so that plans can be drawn up to replace it.

Buttigieg said rebuilding the bridge would obviously take much longer than reopening the port, and that he expected President Joe Biden would soon ask for money from Congress to start the project.

“Rebuilding will not be quick or easy or cheap,” he said.

In a similar incident, a bridge across the entrance to Tampa Bay was struck by a freighter in 1980, causing it to collapse. Its replacement, the Sunshine Skyway Bridge, has large concrete pilings in the water surrounding the suspension bridge’s structural pylons, which are constructed on manmade islands.

Buttigieg, though, said it’s unclear whether even those features would protect a bridge from the largest, heaviest ships in use today, the “NeoPanamax” freighters constructed to take advantage of the new, wider set of locks on the Panama Canal.

“Part of what’s being debated is whether any design feature now known would have made a difference in this case,” he said. “I don’t know how a bridge possibly could withstand the forces that were at play when this vessel, about the same size as a Nimitz class U.S. aircraft carrier, struck the key support beam for that bridge. But we will, as always, learn from the [National Transportation Safety Board] investigation.”

Buttigieg said it was important to get the port open quickly, as it normally handles between $100 million and $200 million of cargo and generates $2 million in wages each day. “These longshore workers, if goods aren’t moving, they’re not working,” he said.