Orange County Fire Authority and Anaheim Fire crews battled the blaze at 3515 W. Savanna Street. Firefighters were called around 1:44 p.m. and had it under control within an hour.
The building was evacuated and no injuries were reported.
Thirty residents have been displaced by the fire. Twelve apartments in two buildings were destroyed. The initial damage estimate was $1.4 million. The cause of the fire was determined to be an accidental cooking fire.
The Red Cross established a shelter for displaced residents at Orangeview Junior High School at 3715 W. Orange Avenue in Anaheim.
Residents had to wait for a first look inside until after fire authorities wrapped up an investigation into what caused the blaze.
One resident said her stove ignited the fire and she only had minutes to get her young son out of the unit and get help.
Another resident said she only had seconds to grab clothes for her son and get to safety.
"We lived here for eight years, eight years," said Yenifer Pascual. "We got everything taken away from us in less than five minutes. That's not fair."
Although crews swiftly put out the flames, at one point they had to access an attic space where some of the fire continued to burn.
"When the fire got up in the common attic space, we had a concern that it may involve the entire attic in the building. So that caused us to initiate some additional fire companies to help us battle that fire," said Fire Marshal Jeff Lutz with Anaheim Fire and Rescue.