The California Highway Patrol confirmed two men and two women were inside a car that crashed Friday night.
The CHP said the driver, 36-year-old Robert Frederick, was traveling at high speeds when he veered off Highway 44 and rolled his car several times.
The crash happened near Tompata Trail around 9:20 p.m.
A witness helped the four people inside get out before the car erupted in flames.
On Sunday the CHP said the woman killed in the crash was 16-20 weeks pregnant.
All four people were taken to Mercy Medical Center, including one by helicopter.
The CHP identified the other people in the car as Kevin Rawlins and Jennifer Jones.
Rawilins suffered moderate injuries and Jones suffered minor injuries.
Frederick suffered major injuries.
He is being charged with felony DUI and second degree murder.
Highway 44 was closed for more than an hour while crews worked to clear the scene last night.