Here's part of the account published by news site Mission Local, which has offices in the building:
As of 8:50 p.m., there is at least one confirmed death, an adult male, according to fire chief Joanne Hayes White. At least four additional people are being treated at an area hospital for smoke inhalation and burn wounds.
The fire began at 6:50 p.m. closer to the 22nd Street side of the building, but quickly spread and escalated. According to Hayes White the fire ran through the building's attic.
It was “Terrible,” said one eyewitness. There were people trying to escape. “A boy on the fire escape with a dog and people just standing around recording,” the witness said.
“I escorted a bleeding man to firefighters,” she added. “No one thought to help.”
Chief Hayes White told media that fire fighters had made at least 11 rescues, several from the fire escapes facing Mission Street, and several more from the building’s internal staircase. Fire fighters “knocked on every door,” said Hayes White.
And from the San Francisco Chronicle's account of the fire:
Ricardo Cedeno, 32, lived in Unit 310 of the building for 12 years. He shared the space with his wife, daughter, sister, mother and stepfather. He stood near the yellow crime scene tape with his 18-year-old daughter, Yessica, checking their phones and gazing at the charred windows of their home.
Little by little, they recalled prized possessions that were likely lost.
“My dress,” Yessica said, speaking of the quinceanera dress she wore three years before.
“My wife’s wedding dress,” her father said.
“It’s devastating,” he said. “We pretty much lost everything. We’re just here trying to see the building one last time.”
Cedeno said he and his daughter weren’t home when the fire broke out, but his mother and stepfather were there. He said his stepfather had been cooking in the kitchen and stepped out to use the bathroom. When he came back, he saw flames coming out of a wall.
His stepfather ran out and began knocking on doors, alerting his neighbors, Cedeno said.
“Everything happened in the blink of an eye,” he said.
Cedeno said the building was mostly home to Latino families, including some loved ones and close friends. It was a close-knit community, he said.
Samantha Hauser, a 25-year-old who works in marketing, lives next to the building, which has residential units on the second and third floors, with commercial space on the first and second floors. She got to the area about 15 minutes after the fire started when it was confined to a few units, but watched from the street as it spread through almost the entire floor in less than an hour.
“I was scared when I first got here,” she said. “I saw flames coming out of the windows, and I just lost all my breath.”