NEW YORK (CBSNewYork) — Ten firefighters were injured early Sunday when an extra-alarm fire broke out in a building in the Flatiron District.

Flames ripped through the five-story mixed-use building at 9 W. 29th St. just after 1 a.m., the FDNY said. The fire broke out on the first floor, which housed a Safenet Computer store.

The fire was later raised to six alarms.

Some 250 firefighters responded to the scene, 10 were injured.

One of the firefighters suffered serious, but non-life-threatening injuries and was taken to NYU Langone Medical Center, officials told 1010 WINS.

The other injured firefighters were taken to Bellevue Hospital Center with minor injuries, officials said.

Officials said the flames spread quickly from the first to fifth floors because the aging building was mostly wood-framed, CBS2’s Hazel Sanchez reported.

The fire was fully extinguished around 7 p.m. Sunday.

“It took me a second to figure out there was a big fire. First I thought it was the church, a passerby told me it was the electronics store next to the church,” Rose Lucas, the manager of a nearby bar, said. “The funny part is, last night they told me it was under control, and I came back to work today at noon and it was still a five-alarm fire, there’s still 10 fire trucks here. So I don’t know if it restarted or if it was never put out to begin with.”

Fire crews used high-expansion foam to extinguish the fire.

(Photo credit: Instagram/beth_worley)

Firefighters pump high-expansion foam into basement to fight a smoldering 6-alarm basement fire at 9 W. 29th St. (Credit: Instagram/beth_worley)

Flatiron District Fire

Firefighters pump high-expansion foam into basement to fight a smoldering 6-alarm basement fire at 9 W. 29th St. (Credit: FDNY)

Flatiron District Fire

Firefighters pump high-expansion foam into basement to fight a smoldering 6-alarm basement fire at 9 W. 29th St. (Credit: FDNY)

Late Sunday morning, the fire was under routine investigation by fire marshals. Fire officials could not say Sunday morning whether any foul play was suspected.