Two Santa Ana residents died in separate accidents after losing control of their vehicles on the rain-slicked San Joaquin Hills toll road.
Walter Skrzekut, 58, was killed about 10:50 p.m. Friday when the 1997 Yamaha motorcycle he was driving slammed into a concrete railing on the northbound transition road to the San Diego Freeway.
Cristina Carachure-Castro, 27, died about 3:20 a.m. Saturday when her 1991 Honda Civic -- traveling at about 70 mph -- crashed into a metal guardrail before careening into a concrete wall near MacArthur Boulevard, authorities said.
Carachure-Castro's three passengers all suffered moderate injuries ranging from a lacerated knee to a broken pelvis.
The causes of the accidents are under investigation, a spokeswoman for the California Highway Patrol said.