Cosgrove said he did not know if the crew saw smoke and/or smelled smoke. It was also not known where the smoke was coming from immediately.
Chris Paolino, a spokesman for the Metropolitan Washington Airports Authority, said six people were taken to an area hospital. He said they were all members of the plane’s crew.
The Alaska Airlines Boeing 737 was carrying 161 passengers, all of whom were evacuated safely at a gate at Dulles and rebooked Monday and Tuesday on other flights, officials said.
Authorities said the cause of the incident is under investigation.