United States commerce secretary John Bryson has resigned following a series of vehicle accidents.
He went on medical leave on 11 June.
Mr Bryson, 68, had been on private business in California on 9 June when he drove into the back of a stopped car, got out of his vehicle, then got back in and hit the other car again. He continued driving and ran into another car.
Police found him unconscious behind the wheel and he was treated for a reported seizure.
In a resignation letter, he says his departure was "a consequence of a recent seizure and medical leave of absence".
Mr Bryson took office last October.