An actor in the Broadway musical "Spider-Man: Turn Off the Dark" was injured during a performance, the latest blow to a show that cost $75 million and has endured plenty of offstage drama.

A spokesman for Broadway's most expensive show says the actor was injured during the Thursday night performance, which was immediately stopped. The actor, Daniel Curry, had a serious leg injury.

Fire officials said they responded to treat a man whose leg got caught in equipment backstage.

Curry was one of several actors who play Spider-Man during each performance, leaping into the audience and swinging over the orchestra.

Actors' Equity Association, a labor union that represents actors and stage managers, issued a statement saying it is "deeply concerned about the Equity member who was injured in the Thursday evening performance" and "has initiated an investigation into the situation, working closely with its members and the representatives of the production."

The musical "Spider-Man: Turn Off the Dark" has become one of Broadway's biggest hits after a difficult start, with six delays in its opening night, injuries to fellow actors, the firing of the show's original director and critical drubbing.

One actor, Christopher Tierney, suffered a fractured skull, a fractured shoulder blade, four broken ribs and three broken vertebrae during a fall in 2010. A lead actress, Natalie Mendoza, suffered a concussion during the first preview performance. A stuntman, Richard Kobak, sued the producers, saying he suffered a concussion, whiplash and two holes in his knees.