An Air Canada flight from Toronto to Washington, D.C., made an emergency landing Sunday evening due to smoke reported in the aircraft. Air Canada Express flight AC7618 landed at Washington Dulles Airport and was evacuated. The plane was to land at Reagan National, another Washington-area airport about 38 kilometres away. Sky Regional, which operated the flight on behalf of Air Canada, said in a statement that all 63 passengers and four crew members were unharmed after exiting the plane on the tarmac. Passenger David Brown told CBC Toronto that the incident happened shortly after 6 p.m. ET and it took about 15 minutes to land the plane after one of the captains announced there was smoke in the cockpit. "We smelled a slight burning odour, but there was no smoke or fire in the cabin," he said. "Passengers were calm and quiet after the flight attendants said we would be making an emergency landing and went through procedures." Passenger Dennis Molinaro said the smoke was coming through the vent above his seat about halfway through the flight. "There was some worried looks on the flight attendants' faces up front, and there was a little bit of a haze closer to the cockpit," he said. "We were a little worried. Then we got the announcement we were going to make an emergency landing, and it was the scariest thing I've been through." He said other passengers were frightened, but composed through the experience. "Everybody was pretty calm and we got out, everybody was orderly getting out." Molinaro said. "Everybody was in the field and relieved and hugging and calling people." He says the staff was "incredibly professional" through the emergency landing. "They were composed the whole time. They kept everybody together organized, calm," Molinaro said. " [The firefighter] said it was the most orderly emergency landing he had ever seen." Metropolitan Washington Airports Authority said authorities are working to determine the cause of the smoke and are working with ground staff to tow the aircraft off the airport runway. The incident has closed one runway at Washington Dulles Airport, but other runways are open. The MWAA says the airport is otherwise operating normally.