Two people suffered major injuries in a head-on collision on Adobe Road after a driver made an unsafe turn, according to the CHP Wednesday.
The collision left as many as four people trapped inside their mangled cars and firefighters had to cut them free.
The 10 p.m. crash occurred near Frates Road Tuesday night.
Driver Ashleigh Sgrulloni, 23, of Sonoma was turning on the two-lane east Petaluma route just before the collision. Her Ford 500 got into the path of another vehicle, said CHP Officer Jon Sloat.
The Ford was hit by a Mitsubishi Lancer driven by Joseph Schenone, 56, of Rohnert Park.
Schenone, who was alone, suffered major injuries including broken leg bones, said Sloat.
With Sgrulloni were Derek Sgrulloni, 28, of Sonoma and Gianna Sgrulloni, 2, of Sonoma.
Derek Sgrullino had major injuries. Ashleigh Sgrulloni had minor injuries and the little girl, who was properly strapped into a child's car seat, was not injured, Sloat said.
All four were taken to Santa Rosa Memorial Hospital. Schenone and Derek Sgrulloni were in serious condition late Wednesday.
Two Rancho Adobe fire engines and crews from two Lakeville engines and a Petaluma engine responded with two ambulances.
Impairment wasn't not considered a factor in the collision, Sloat said.