Climate change is increasing the probability that urban communities with lengthy histories of land-based industrial pollution and ongoing residential segregation will experience more frequent and destructive flooding in the years ahead. This paper investigates where these past, present, and future forces will converge to potentially produce a new type of climate injustice, as the flooding of former, or ‘relic,’ industrial sites threatens to transport sequestered industrial contaminants off site. Merging property-level flood-risk projections from the First Street Foundation with historical data on former hazardous manufacturing facilities in 6 U.S. cities, we identify more than 6000 relic industrial sites with elevated flood risk over the next 30 years. Exploratory spatial analysis reveals that these sites cluster spatially to create identifiable zones of cumulative impact, within which as many as 560 thousand residents and 229 thousand housing units are currently located. Spatial multilevel modeling further indicates that socially vulnerable groups (i.e. racial minorities, those with lower incomes, and those residing in less autonomous housing) are consistently and disproportionately likely to live in these areas. These findings highlight the need to develop new strategic plans to rethink site-based strategies of remediation and to engage residents of historically marginalized communities in planning efforts as government agencies at all levels work to make their cities more resilient and environmentally just in the age of climate change.