NEW YORK, OCT. 26 -- Violence flared at the Daily News today as more than 2,500 union workers struck the nation's second-largest metropolitan daily newspaper and management began immediately to fly in replacements.

The strike, which has been anticipated for months, could destroy the unions, the financially troubled paper, or both. At least two delivery trucks were firebombed and three replacement workers were hospitalized. Police reported 11 arrests.

"The Daily News is now dead," said Edward Edelson, science editor and a 19-year veteran of the paper. "It might take a long time and it might be quick. But it will never be what it was."

Management officials believe the only way to save the paper is to make certain its past is buried as quickly as possible. They say the paper, which has lost more than $100 million and 700,000 readers during the past decade, has an overpaid staff that is far too large -- essentially the same size as it was in the 1930s, when circulation was 3 million and production processes were more labor-intensive.

Modern technology has made it possible to produce such a paper at a greatly reduced cost, but New York is a staunch union town and no newspaper has succeeded yet without union help or agreement.

The News, second in circulation to the Los Angeles Times, will have to convince advertisers that it can produce a reliable paper in the coming weeks if it hopes to attract essential Christmas ads. New York's economy is in a recession. Many U.S. newspapers have been suffering from severe declines in revenue and this city's papers have been hit harder than most.

If advertisers believe the paper is not being delivered or read by its usual 1.18 million customers, it could be devastating to News revenues. But if the paper succeeds in circulating during the coming weeks, the parent Tribune Co. has plenty of money to see it through the transition.

"We are now in the process of replacing those workers who left their jobs," said News spokeswoman, Lisa G. Robinson. "When individuals voluntarily leave their positions, it is a strike. This is their choice. Management also has choices to make."

Using management and replacement workers, the paper produced what it said was 611,000 copies of its Friday paper, slightly more than half its usual daily circulation. Few newsstands in Manhattan carried it, however, and delivery was spotty in the city's other boroughs.

The strike began Thursday night, when workers belonging to the 700-member newspaper drivers' union left their jobs after a dispute over whether a member with a knee injury could do his job while sitting. Nine of the paper's other ten unions, including the 800-member Newspaper Guild unit that represents the newsroom staff, have said they will honor picket lines.

Daily News officials said today, however, that those who do not report to their jobs by midnight risk losing them. The paper said it would continue printing at all facilities. Management officials have been trained by the Chicago-based parent company to run presses and perform other tasks necessary to produce a paper.

Union officials asserted today that the paper forced the strike and said management has been seeking to cause one for 10 months, since labor negotiations began. All contracts expired in March.

"This isn't something that can heal, "said George McDonald, president of the Allied Printing Trades Council, the unions' umbrella organization. "New York will have to lose another paper. We have bent over backwards but management doesn't want to try."

Most analysts say New York, which once had 12 prosperous dailies, can no longer support more than two or three. The other city papers are the New York Times and the tabloid New York Post and New York Newsday. Last month, the Post came within hours of closing before workers agreed to cost-saving measures.

"It's not a time to be looking for work," said Gregory Taylor, a Guild member and computer analyst. "We all know that. But the Daily News isn't just a bunch of stories. It's the people who make it. If you lose that, you lose the paper."