4-alarm fire races through building in San Francisco's Hayes Valley

Flames from a four-alarm fire raced through a building under construction in San Francisco's Hayes Valley, causing traffic impacts in the neighborhood but fortunately no injuries.

SAN FRANCISCO - Flames from a four-alarm fire raced through a building under construction in San Francisco's Hayes Valley, causing traffic impacts in the neighborhood but fortunately no injuries.

The fire at Octavia and Oak streets was reported at 6 a.m. It's unclear how it started.

Fire Chief Jeanine Nicholson arrived at the fire to help manage the situation and provide updates to the public.

The site is an apartment building under construction, which meant no one had been living there and no one was hurt.

But it also means there was no sheetrock, or anything to slow the flames.

"It's like a pile of matchsticks," Nicholson said. "It's like Burning Man."

4-alarm fire races through building in San Francisco's Hayes Valley

Flames from a four-alarm fire raced through a building under construction in San Francisco's Hayes Valley, causing traffic impacts in the neighborhood but fortunately no injuries.

Video showed massive flames erupting from the wooden frame of the four-story building and firefighters dousing the structure with water. At one point, the building collapsed on itself.

Neighbor Kristine Choi woke up to see the building next door to her ablaze. "Oh, sh--," she said, as she filmed video on her phone.

Despite the massive flames, the fire didn't spread to any other buildings in the residential neighborhood.

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By 7 a.m., most of the flames had been put out by the firefighters, who had a good handle on the blaze.

Still, firefighters said they would need to stay on scene through much of the day, and surrounding streets would be affected.

No evacuations were necessary, but six people who live nearby were displaced temporarily.