BASEL, Switzerland (AP) _ Herbert Wernicke, a German avant-garde opera designer whose productions appeared at major theaters across Europe, has died, the Vienna State Opera said Wednesday. He was 56.

Wernicke died Tuesday in Basel, Switzerland, where he was working on the set for Handel's oratorio ``Israel in Egypt'' at the city's main theater. The cause of death was not given. The Austrian newspaper Salzburger Nachrichten reported Wernicke collapsed in the street and could not be revived.

A prolific designer, Wernicke's current projects also included a production of Wagner's Ring cycle for the Bayerische Staatsoper in Munich, Germany.

His production of Ernst Krenek's 1925 opera ``Jonny spielt auf'' was to open in Vienna in December.

Born March 24, 1946, in Augge in Germany's Black Forest, Wernicke studied piano, flute and conducting at the conservatory in Braunschweig, and then at the Fine Arts Academy in Munich. His debut as an opera designer was a 1978 production of Handel's ``Belsazar'' in Darmstadt. He later worked at the operas in Berlin and Frankfurt, as well as in Paris, Basel and Brussels. Wernicke also was a regular at the Salzburg Festival in Austria.

In the past year, he produced operas at London's Covent Garden and at Aix-en-Provence in France. His first U.S. production, Richard Strauss' ``Die Frau ohne Schatten'' opened at the Metropolitan Opera in New York in December.

Last year he was awarded the Bavarian Theater Prize for his production of Bach's ``Actus Tragicus'' in Basel.

Ioan Holdender, director of the Vienna State Opera, said he was stunned by Wernicke's death.

``Only on Sunday, my technical director met Herbert Wernicke in Basel and brought back the stage plan for 'Jonny spielt auf.' Everything was wonderful,'' he told the Austrian Press Association. ``I don't know what I'm going to do now.''

``I don't know of any other producer who could combine costume, scenery and direction so completely into a single concept.''