PATERSON, N.J. (AP) _ A furiously burning fire destroyed a downtown block of stores and offices and jumped to a second block Thursday as scores of firefighters battled the flames. One firefighter was missing and presumed dead.

The fire was still raging more than 10 hours after it began, fed by winds gusting more than 25 mph, said Deputy Fire Chief Norman Morley.

''We're talking about a major disaster here,'' said Mayor William J. Pascrell Jr. Destroyed buildings were valued at an estimated at $13 million to $14 million, he said.

''It will have a tremendous impact - it's the heart of the downtown shopping area,'' Pascrell said.

After consuming one block in this city of more than 139,000, flames jumped to a second block and burned four or five buildings before firefighters stopped its spread, Pascrell said. No homes burned.

The fire broke out at the Underground 2 clothing store on Main Street shortly before 6 a.m. and spread quickly through the block, officials said. Passaic County Prosecutor Ronald Fava said investigators had not been able to get into the building to determine how the blaze started.

About 60 firetrucks responded to the blaze.

One of the firefighters who entered the building where the fire began was missing and presumed dead, Pascrell said.

''Apparently they went in, it got too intense and they came back out, and then they had a head check and that's when they realized he wasn't there,'' Pascrell said. ''They went back in again, and the smoke was so thick that not even their lights would work, they couldn't see. They felt their way all through but they couldn't find him.''

Four firefighters and a passer-by were treated and released at Barnert and St. Joseph's hospitals, spokesmen said. Pascrell said he, too, was treated for smoke inhalation as well as elevated blood pressure after spending seven hours monitoring the firefighting efforts.