"Lost" crashed in the ratings this week, hitting an all-time low for a new episode.

ABC's drama about plane crash survivors stranded on a mysterious island drew an estimated 12.8 million viewers Wednesday, according to preliminary figures from Nielsen Media Research.

That's well off the peak of more than 20 million for the drama that became an instant sensation when it debuted in September 2004.

The show is filmed in Hawai'i and is a keystone in the state's $100 million-a-year film industry.

But the lost viewers are no immediate indication that the show's future is threatened, said Walea Constantinau, film commissioner for the Honolulu Film Office.

"I would not feel cause for alarm that this would indicate anything negative about the show," she said. "It's still so, so incredibly popular."

Changing time slots and going on a long hiatus, as "Lost" did this season, can affect a show, she said, and it could take time for "Lost" to regain its popularity.

"It's important for people to know that really a different time slot makes a big difference," Constantinau said. "It is a whole different viewership in a totally different time. It changes everything."

Donne Dawson, manager of the Hawai'i Film Office, said that ABC is still putting out "a quality product" that will keep fans entertained.

"Certainly if there was cause for alarm, along these lines, I would have heard rumblings about it, and I have not," she said. "We'll have to wait and see what happens. I still have a real strong feeling that they're doing just fine."

ABC has worked hard to try to protect the show, which helped turn the network's fortunes around, moving it to a later time slot on Wednesdays this year to steer clear of Fox's blockbuster "American Idol" and CBS' increasingly strong "Criminal Minds."

After "Lost" fans complained about reruns interrupting the show's serial flow last season, the network tried an experiment: It split the current season in two, airing six episodes before an extended break and then resuming with 16 additional episodes.

The show's Feb. 7 return was heavily promoted and drew nearly 14.5 million viewers. But the bounce didn't last, with the show slumping this week.

Although protected from top-rated "American Idol" in its new 9 p.m. time slot (10 p.m. Eastern time), "Lost" now has the disadvantage of trying to draw viewers at an hour when fewer people are watching television. And on Wednesday, Valentine's Day put a 7 percent dent in overall TV viewership.

In the show's defense, ABC noted that it beat the competition among the advertiser-favored young adult crowd, drawing 7.3 million viewers age 18 to 49 compared with the 5.8 million that tuned in to "CSI: New York" on CBS.

"Lost" also handed ABC nearly 4 million more viewers in the time slot compared with last year, when the short-lived drama "Invasion" aired, the network said.

But there's no question that "Lost," once riding big ratings, buzz and cachet, has lost significant ground.

Some fans complain the story has become confusing and unsatisfying. The show, named best drama at the 2005 Emmys, was shut out at the 2006 ceremony.

The show still has plenty of die-hard Hawai'i fans.

"I am still drawn back to it," said Jennifer Self, a Waikiki bar manager. "I plan my work schedule around this."

She and her husband, Christian, rarely miss an episode.

"It's keeping me on tenterhooks," he said. "I just can't wait for the next week. I want to know — man, I need to know — the whole mystery of the island."