MANHATTAN — A massive fire engulfed a Chelsea apartment building sending flames spewing from the windows onto West 17th Street Tuesday morning, officials said.

The blaze erupted on the fourth floor of 221 W. 17th St., near Seventh Avenue, which was unoccupied because it was under renovation about 3 a.m., an FDNY spokesman said.

It spread to the fifth and sixth floors, ultimately damaging every floor of the building, fire officials said.

"We saw the flames. It was intense. They were about 6-feet high and out the window. They were bright orange," said Alexis Hovey, 33, who lives across the street.

The fire spread quickly because the building was under renovation, officials said. There were combustible materials, the sprinkler system had been removed along with other fire protection features, officials said.

"There were a lot of open shafts, a lot of holes in the floors. There was spaces between the walls that really led to rapid fire growth, and fire spread throughout the building," said FDNY Chief of Department James Leonard.

About 198 firefighters brought it under control about 7:10 a.m., officials said.

#evacuating #fire #fdny #w17th A video posted by Brett Lindsey (@brett_lindsey) on Oct 20, 2015 at 2:26am PDT

There were no reported injuries. The only person who was known to be there at the time, a watchman guarding the site, was uninjured, officials said.

Fire marshals will investigate what sparked the blaze, officials said.

Three buildings across the street were evacuated because officials worried the burned out site would collapse.

"We're afraid of the front of the building collapsing into those buildings across the street," Leonard said.

"At this time, the building is in major danger of collapse, so we are keeping everyone away from the building," the chief added.

The Department of Buildings was also called to the scene, according to its website.

Many neighbors shoeless ran into the street wearing robes and pajamas with crying children in tow, they said.

"The concierge was calling the apartments and people were banging on doors and we were told we had to evacuate," said Kay Johnson, 31, who lives across the street.

"It was very smoky. It was very crazy. I rushed out with no jacket and wearing slippers," she added.

"It was terrifying," Johnson said.

Big Fire on 17th between 7th and 8th ave . #fdny #nypd on the scene in full force. I hope everyone's okay. A photo posted by Dan Ryan (@thedailydanryan) on Oct 20, 2015 at 12:30am PDT