Architects working on preserving Notre-Dame are rushing to cover the cathedral's before rain can cause further damage, BBC reports. Showers and even possible thunderstorms are forecast for the French capital on Tuesday evening. The cathedral's vault, which partly collapsed in the fire, is already partly waterlogged after fire-fighting efforts. Architects fear that heavy rainfall could result in further collapse. There are already plans to erect a large, purpose-built "umbrella" on the roof of the landmark, which will have its own peak and protect the structure while reconstruction takes place.