  A giant molecular cloud has been detected surrounding the supernebula in NGC
5253, revealing details of the formation and feedback process in a very massive
star cluster. "Cloud D" was recently mapped in CO J=3-2 with the Submillimeter
Array. The cloud surrounds a currently forming massive cluster of mass ~10$^6$
$\rm M_\odot$ and luminosity ~10$^9$ $\rm L_\odot$. Cloud D is hot, clearly
associated with the cluster, yet kinematically relatively quiescent. The dust
mass is ~15,000 $\rm M_\odot$, giving a gas-to-dust ratio of ~50, nearly an
order of magnitude lower than expected for this low metallicity galaxy. We
posit that enrichment by the cluster, leading to a stalled cluster wind, has
created the unusual conditions in Cloud D. The absence of current mechanical
impact of the young cluster on the cloud, in spite of the presence of thousands
of O stars, may permit future generations of stars to form near the massive
cluster.
