BOSTON -- Several people on a Boston-bound flight were taken to a local hospital Monday when they reported feeling sick after landing at Logan International Airport.

Five U.S. Air crew members complained of flu-like symptoms shortly after landing in Boston and were taken to Massachusetts General Hospital, Massport officials said. EMS officials said the crew members had elevated carbon monoxide levels and were given high-flow oxygen at the hospital.

"It is hard to fathom an idea where you can fill up an plane with enough carbon monoxide where just the crew would get sick and not everybody else," said Dr. Aaron Waxman, of Massachusetts General Hospital.

The crew and passengers were on a different plane at Reagan-National Airport in Washington, D.C., when strange fumes were reported, U.S Air said. Everyone was moved to a different plane and then flew to Boston.

"They are continuing the investigation to find out exactly what was the cause for people to become light-headed, dizzy. That is done by a lot of the agencies here at the airport, federal agencies and U.S. Air. Our main concern was with taking care of the patients and making sure they had immediate care and were transported to the hospital," said Rich Serino, of Boston EMS.

None of the 81 passengers on board Flight 2022 reported feeling sick.