Broadway's costly "Spider-Man: Turn Off the Dark" has been delayed again to March 15 to "fine-tune" the high-tech production and work on a new ending even as it proves a hit at box offices in previews.

Producers made the announcement late on Thursday following a series of accidents during preview performances of the $65 million show -- Broadway's most expensive ever -- that has injured four actors, as well as reports of new staging and music from director Julie Taymor and U2's Bono and The Edge.

But even in previews, fans have turned out in droves for the production that is based on the crime-fighting comic book hero who has the powers of a spider.

Separately on Thursday, The Broadway League said "Spider-Man" was the best-selling production of the week between Christmas and New Year's Eve, raking in $1.588 million at its box office.

"We are so grateful for the enthusiastic audiences who have been coming to see 'Spider-Man: Turn Off The Dark' and we are dedicated to giving them the very best show we can," Taymor said in a statement.

Producers Michael Cohl and Jeremiah J. Harris said the new delay, which pushes back the opening from a previous date of February 7, was done to "fine-tune aspects of the show, including the new ending." Cohl said the date should give the creative team plenty of time to ensure a good show and added this new delay will be "the final postponement."

"We are looking for the extraordinary here, we are nearly there," Bono and The Edge added in a joint statement.

The show features massive sets and numerous stunts in which cast members soar through the air above the audience. But all the high-tech wizardry has not been without problems.

Four actors have been injured. Most recently, actor Christopher Tierney, 32, fell 30 feet from a platform and broke his ribs. He was hospitalized and had to have surgery. Following Tierney's injury, producers canceled two performances while checking safety measures.

The show had been delayed four times. Before the February 7 date, it had been set to open on January 11. Preview performances began on November 28.

Taymor and the producers have noted that many shows work out kinks and problems during previews, and "Spider-Man" is no exception. So far, audiences haven't seemed to mind.

The show's recent best-selling box office tally just beat the ticket sales of long-running musical "Wicked," which also took in $1.588 million, when numbers are rounded up, but it was $58 shy of the "Spider-Man" figure, according to the Broadway League.

"Wicked," still holds the box office record for the highest grossing show in a single week, $2.22 million in the most recent week between Christmas and New Year's Eve.