The phrase "smoking ruins" refers to a place that has been completely destroyed by fire or war, with smoke rising up from the remains. It implies that there is nothing left or very little left of the place. Full definition
The story opens with Washington, D.C. in smoking ruins. (nextprojection.com)
Better a smoking ruin of ash and stone than to deface our nations cathedral by uniting qu eers as if they were deserving people. (religion.blogs.cnn.com)
In less than 40 years, the temple would be a smoking ruins. (religion-online.org)