SEATAC, Wash. — The Lufthansa plane that diverted to Seattle because of an electrical smell in the cabin is returning to Germany without passengers.

An airline spokesman in New York, Nils Haupt, says passengers were not re-boarded because technicians could not find the cause of the odor. The crew is flying the plane to Munich or Frankfort on Friday so it can be thoroughly checked.

The Airbus A340 was on its way from San Francisco to Munich Thursday night when it diverted to Sea-Tac Airport. Haupt says three flight attendants and a passenger who felt dizzy were treated on board.

There were 323 passengers and a crew of 18 on Flight 459. Passengers were put in Seattle hotels overnight. Haupt says most have been booked on flights to Europe on other airlines.