Sleeping residents woke up to blaring fire alarms, thick smoke and ferocious flames.
Melvin Dahlin was one of them.
"Twelve inches thick of smoke and it was coming through the front door under the sides and the top. I opened the front door, and there was just a blanket of smoke," he said.
The only other way out was the balcony and that's where Dahlin went to wait. However, the situation at his neighbor's was worse than his own.
"Huge blast of flame looked like about two feet in diameter. Just coming out rapidly like a blast furnace," he said.
More than 100 firefighters responded to the blaze. They moved fast, plucking more than a dozen people from balconies. They rescued or located 97 people between 72 apartments. But one man is still missing and officials don't know if he's inside.
The six-alarm fire was still flaring up more than 12 hours after it started, making it too dangerous for crews to go in.
"It was deep seeded in the third floor but also we're struggling with the roof-covering materials and some hidden fire that, because of the original amount of fire, the building is unstable for us to go inside. And so there's some areas of fire we just can't get to," said Redwood City Deputy Chief Stan Maupin.
Twenty-one people went to the hospital with minor to moderate injuries, including three firefighters.
The fire department brought in cadaver dogs but they couldn't get inside so they sent them home. They'll be back Monday morning when authorities begin their investigation.
The cause of the fire remains unknown.