Four 18-year-olds were hurt last night when their car overturned into a ditch on the south-western bypass of Karnobat, Burgas regional police said.
The girl in the car has a bruised lung. She is in the Heart and Brain hospital for observation.
The crash happened at about 11.37pm. The driver of the Fiat Punto, a young man from Karnobat, lost control and the car rolled into the roadside ditch, police say. His tests for alcohol and drugs were negative.
Three friends his age from the town were with him: two boys and a girl.
The driver has light surface wounds on both arms, and one of the boys has a light surface wound on his head. Both refused to go to hospital for a further check.
The fourth passenger has no serious visible injuries and also refused to be taken to hospital.