The iconic Hollywood sign is shown on a hillside above a neighborhood in Los Angeles California, U.S. [Source: Reuters Business]

Thousands of film and television writers headed to picket lines for their first work stoppage in 15 years.

This sent Hollywood into turmoil and disrupted TV production as the industry wrestled with the shift to streaming.

The Writers Guild of America (WGA) said its leadership unanimously supported a strike after failing to reach an agreement for higher pay from studios such as Walt Disney Co (DIS.N) and Netflix Inc (NFLX.O).

The guild was seeking changes in pay and the formulas used to compensate writers when their work is used by streaming services, among other proposals. The WGA estimated its changes would cost about $429 million a year, according to a negotiations summary shared on Twitter and verified by Reuters as authentic.

Striking writers were expected to picket NBCUniversal’s Peacock presentation to advertisers Tuesday in New York, where the streaming service is planning to tout its growth and new ad technologies and showcase upcoming content.

For viewers, the strike’s first impact will be seen on late-night talk shows such as ABC’s “Jimmy Kimmel Live,” NBC’s “The Tonight Show Starring Jimmy Fallon” and the NBC’s “Late Night with Seth Meyers,” which count on teams of writers to pen topical jokes for programs recorded on the day of broadcast.

The Fallon and Meyers shows will begin airing repeat episodes immediately, a person familiar with the situation said. “Kimmel” also is expected to enter reruns.

Conglomerates are under pressure from Wall Street to make their streaming services profitable after pumping billions of dollars into programming to attract subscribers.

The rise of streaming has eroded television ad revenue as traditional TV audiences shrink.

The last WGA strike in 2007 and 2008 lasted 100 days. The action cost the California economy an estimated $2.1 billion as productions shut down and out-of-work writers, actors and producers cut back spending.

The Alliance of Motion Picture and Television Producers (AMPTP), which represents studios, said it had proposed “generous increases in compensation,” and was willing to increase its offer.

But it said it objected to WGA demands that “would require a company to staff a show with a certain number of writers for a specified period of time, whether needed or not.”

Writers say they have suffered in the streaming TV boom with shorter seasons and smaller residual payments.

The one late-night program running new episodes is Fox News’s “Gutfeld!,” whose writers are non-union. ABC’s morning talk show “The View” also will continue airing new shows.

Another TV program may be disrupted depending on how long the strike lasts.

Writers said they were willing to walk off the job because changes from streaming have made it difficult for many to earn a living in expensive cities such as New York and Los Angeles.

Half of TV series writers now work at minimum salary levels, compared with a third in the 2013-14 season, according to WGA statistics. The median pay for scribes at the higher writer/producer level has fallen 4% over the last decade.

Artificial intelligence (AI) is another issue at the bargaining table.

The WGA wants safeguards to prevent studios from using AI to generate new scripts from writers’ previous work. Writers also want to ensure they are not asked to rewrite draft scripts created by AI.

With a potential strike looming, production already had ground to a halt in Los Angeles. Film LA, which issues permits for filming in Los Angeles, said it had no shoots for scripted shows scheduled for Tuesday or the rest of the week.

If the work stoppage becomes protracted, the networks will increasingly fill their programming lineups with unscripted reality shows, news magazines and reruns. It also could delay the fall TV season. Writing for fall shows normally starts in May or June.

Netflix may be insulated from any immediate impact because of its global focus and access to non-U.S. production facilities.