  We study actions of locally compact groups on von Neumann factors and the
associated crossed-product von Neumann algebras. In the setting of totally
disconnected groups we provide sufficient conditions on an action
$G\curvearrowright Q$ ensuring that the inclusion $Q \subset Q \rtimes G$ is
irreducible and that every intermediate subfactor is of the form $Q \rtimes H$
for a closed subgroup $H<G$. This partially generalizes a result of
Izumi-Longo-Popa [ILP98] and Choda [Ch78]. We moreover show that one can not
hope to use their strategy for non-discrete groups.
