One man was killed and another injured in a crash just east of Sonoma late Friday night, the CHP said.

The men, whose identities were not released Saturday, were heading south on Seventh Street near Castle Road just before midnight when their 2010 Porsche Cayman drifted into the right shoulder and hit a tree, Napa CHP Officer Ryan Snider said. The car then became airborne and rolled before it slammed into a fence and another tree, coming to rest on its roof, he said.

Snider said the 28-year-old driver, of Mountain View, died at the scene.

The passenger, 28, of New York, suffered major injuries and was flown to Napa’s Queen of the Valley Hospital. His condition was unknown Saturday.

It’s unclear why the driver drifted off the roadway, Snider said. Officers are still investigating whether alcohol could have been a factor, he said.