A solo rollover accident sent two people to the hospital Tuesday night, according to the California Highway Patrol.
CHP officials said Reyna Estrada, 33, of Los Angeles was driving a 1998 Toyota minivan northbound on Interstate 5 at 8:12 p.m. south of Herndon Avenue when she, for an unknown reason, allowed the vehicle to swerve to the left.
The Toyota traveled onto the median, overturned several times and landed on its roof.
Estrada's two sons, 11 and 4, were passengers in the minivan.
CHP officials said debris from the minivan struck a 2012 Volvo southbound on I-5.
The driver of the Volvo, Javier Contreras, 42, of Fontana, was not injured.
Estrada and her 11-year-old son were taken to Community Regional Medical Center in Fresno.
Estrada has major injuries and her son has moderate injuries, according to the CHP.
Estrada's 4-year-old son was not hurt.