FALLING DOWN: Martin Margiela’s fall collection was all about deconstruction, so it was only fitting that it should be staged in the unfinished basement of the Palais de Tokyo contemporary art museum. It turned out the wooden bleachers guests sat on were also of the rough-hewn variety. A loud pop resounded after Kanye West and Elly Jackson, front woman of La Roux, took their seats. “The seat just moved and it was quite scary. Something clicked out of place,” said Jackson. Still, with Renzo Rosso – president of Only The Brave, the holding company that owns Margiela – staying put, nobody asked to be moved. Jackson, who is recording her next album, said she was taking a weekend off in Paris as a treat ahead of her birthday on March 12.