Baltimore-Washington International Thurgood Marshall Airport remains closed tight today -- with no flights coming in or out but one.

BWI chief executive Paul J. Wiedefeld said a twin engine Beechcraft plane landed during the peak of the snowstorm at 12:01 a.m. He said the "mini-cargo" run was delivering canceled checks for bank processing.

Wiedefeld said he did not know where the flight originated and did not identify the pilot. The airport said there were no problems with the landing.

"It was uneventful except for him. He was a little nervous," he said. The pilot broke no laws and did nothing improper, Wiedefeld said.

The airport administrator said it is up to the airlines whether scheduled flights will resume Sunday. He said the airport would have runways cleared and ready if the airlines are ready to fly.

Airport crews were spending their Saturday performing a hearculean task of plowing, melting and hauling away snow to prepare the airport reopening.

 Wiedefeld said the were helped by the fact that all but one airliner left Baltimore before commercial operations shut down Saturday -- leaving the gates and taxiways free of aircraft that would have obstructed plows.