A bit of a detour Friday for passengers leaving Washington, D.C. On their way to Chicago on board one American Airlines flight. That's because there was an unknown illness on that flight.

An American Airlines jet had to make an emergency landing in Dayton, this morning, when something went wrong on board.

It turns out two flight attendants were complaining of dizziness and four passengers later fainted. But when the captain learned of the illnesses, he decided to divert the plane to Dayton for an emergency landing.

On the way, the captain also decided to drop down the oxygen masks on the Boeing 7-37. Once it landed, all 140 people walked off the plane but two were taken to the hospital.

Flight 5-47 originated from Reagan National Airport in Washington, D.C. and was headed to Chicago's O'Hare Airport.

At the point, it's still not known what caused the illnesses but, we're told, American Airlines is conducting a thorough investigation.