The marble blocks of the 25 domes were tied to one-another and embedded in the brick masonry over the domes with iron dowels. The rain water spouts from the inaccessible roof got blocked resulting in large quantities of rain water collecting on roof. This resulted in the rapid deterioration of the roof and large scale water ingress from the roof leading to the corrosion, rusting and expansion of the iron dowels. The significant pressure from the expanding iron dowel led to bursting of the marble blocks in all parts of the mausoleum – domes, arches, facade, pendentives and even the column capitals – threatening structural failure and collapse of the structure.