2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/60952We give an explicit combinatorial description of the irreducible components of the singular locus of a Schubert variety in a flag variety of type A. This implies a conjecture of Lakshmibai and Sandhya.16 pages, 38 figures, in FrenchAlgebraic Geometry14M15text