Authorities said a Ford Excursion flipped several times and burst into flames on the Beach Boulevard off-ramp from the 5 Freeway at about 10 p.m. Monday.
Landen Cadenas was driving when he spotted the burning vehicle and pulled over to help.
"I ran over there, opened the door, ran over there and I heard a lady screaming and seen a female trying to pull a girl out, so I just helped her by pulling the female that was in the car out of the window," Cadenas said.
He was able to pull two women out of the burning vehicle.
"I don't want to see her burn, so my first instinct was, wow, pull the girl out of the car," Cadenas said.
Three women who were thrown from the car were pronounced dead at the scene. The victims were identified as 24-year-old Elda Nada-Mayo, 49-year-old Angela Cid-Del Prado and 40-year-old Sara Flores, all from the city of Downey.
The other two victims, the driver and a 17-year-old passenger, were taken to UC Irvine Medical Center in critical condition.
The women were on their way back from a church service at Crystal Cathedral in Garden Grove. Pastor Mario Krawchuk said the women were going through the process to become members at the church and attended services often.
Krawchuk said people came together to pray for the family on Tuesday and plan to again in the evening.
"We feel really sorry about it. I know God is in control. Sometimes we don't know what, how, why these things happen, but we pray for the family," Krawchuck said.
According to CHP officers, only the driver was wearing her seatbelt. It's not clear what caused the vehicle to overturn. California Highway Patrol is investigating the crash.