The accident was a scary climax to the saga of “Shogun,” one of the most expensive musicals ever with a cost estimated from $6 million to $10 million. Appropriately for its Buddhist theme, “Shogun” is a property of many incarnations: first a huge best seller by James Clavell, then a big TV mini-series, now a Broadway blockbuster. The supernaturally inclined may wonder what might have happened to Casnoff had the stage of the Marquis Theater not been blessed last July in a ceremony starring five Shinto priests flown in from Japan. One of those priests was Haruki Kadokawa, the colorful Japanese publishing and movie mogul who’s a heavy “Shogun” investor and coproducer. As one of Kadokawa’s aides said: “It’s not easy for the gods in an environment like Manhattan.”

“Shogun’s” problems started in 1981, when Clavell asked choreographer director Michael Smuin to develop a musical based on his novel. Several years and scripts later, the show staggered into Washington’s Kennedy Center under the weight of 70 tons of scenery, an awesome array of technology and the most problematic book seen in Washington since the national budget. During four weeks of previews at Kennedy, the show lost some of its threehour-plus length and its leading man, the English actor Peter Karrie, who was roasted by the critics (“completely at sea when called upon to act,” said The Washington Post) and was replaced by Casnoff.

Casnoff is at sea only in the very first scene, a howling, laser-crackling storm in which his ship is wrecked on the Japanese coast in 1600. Later the show tops itself with an earthquake, in which the stage splits and heaves into burning crevasses. The quake has fewer crevasses than the show’s book (credited to John Driver), which spills forth its tangled plot for the audience to untangle. Most won’t get past the basic story, in which English seadog John Blackthorne (Casnoff), hurled into an alien culture, comes to love it and the Lady Mariko (June Angela), while they get caught up in power wars between overlord Toranaga (Francis Ruivivar) and his rivals.

Challenging such techno-pop monsters as “Les Miserables” and “Phantom of the Opera,” “Shoguns” creators come UD with kitsch Kurosawa. The best moments are the smallest, like a lovely song, “Cha-No-Yu,” in which Mariko and Buntaro (Joseph Foronda), the husband she’s been unfaithful to, turn a tea ceremony into a quietly ironic expression of their dilemma. Paul Chihara’s music might have worked well in a simpler, clearer context. The show is so dense that you get “Shogun”-shy, despite the huge cast with appealing Asian American performers like the pure-voiced Angela and dancers like Jo Ann M. Hunter and Eric Chan. There’s a Broadway-bitchy impulse to jump all over an expensive mess like this. The fact is that “Shogun” has been betrayed by inflated ambitions that have deflated the final product.