A stubborn six alarm fire in Manhattan kept nearly 250 firefighters busy all day Sunday.

Flames broke out in a commercial building on West 29th Street early Sunday morning, rattling those who live in the neighborhood.

"It was so loud there were fire trucks going up and down the street," said Chelsea resident Kimberly Doyle. "Every five minutes the kids kept waking up because my son's got a sleepover and they were crying because it was so loud."

Roaring fire alarms signaled a progression from one to six alarms, requiring the manpower of 240 firefighters. 

The fire chief says it started in the basement of the Safenet Computer store near Fifth Avenue. 

They were able to knock down most of the blaze, attacking it with high expansion foam to cool smoldering hotspots.

Then, hours later, another fire sparked. 

"It burned for a considerable amount of time in a confined area, between ceiling space," said FDNY Commissioner Daniel Nigro. "This type of structure is very difficult from outside the building to get the water in the right place to get the fire out."

While firefighters worked to knock down the fire, police blocked 28th, 29th and 30th Streets between Fifth & Sixth Avenues, interrupting the flow of business in the area. 

"The one with the German Shepherd, couldn't get across the PD line, so I said 'Hey this is a client,' I had to get him across, people have been affected, definitely," said Julian Toussaint, a barber in the neighborhood.

"When we came and opened in there was a hallway full of smoke," said restauarant owner Mohammad Asharif. "We just put on our exhaust system until all the smoke was gone."

Thankfully, no one was seriously hurt but ten firefighters were treated for heat exhaustion and smoke inhalation.