A Tucson man was killed in a single-vehicle accident near Marana on Interstate 10 early Thursday morning, the Department of Public Safety said.

The crash occurred shortly after 2 a.m. about a mile from the Pinal County line when an eastbound 2003 Ford Focus drifted into the shoulder on I-10. The woman driving may have fallen asleep and driven into the rumble strip, said Jim Oien, Department of Public Safety spokes-man. She was startled, drove into the median and lost control of the vehicle, according to the DPS.

The car's passenger side then struck a large tree in the median, tearing the vehicle in half. The rear wheels and trunk ended up near the westbound lanes and the front half of the car came to rest in the median.

The passenger in the car, 26-year-old Juan C. Jimenez, was killed instantly and the driver, a 21-year-old Tucson woman, was taken to University Medical Center with non-life-threatening injuries.

Neither Jimenez, who lived in the 5500 block of East 25th Street, nor the driver were wearing seat belts, Oien said. The relationship between the pair was not known Thursday.

No citations had been issued pending the completion of an investigation.