Debris flows are among the most destructive hydrological consequences of fires in steep watersheds. The high likelihood of catastrophic wildfires in the western United States and the encroachment of human activities into steep fire-prone areas have created the need to better understand, predict, and mitigate these hazards. This article highlights recent advances in understanding post-fire debris-flow generation and provides an overview of the evolution of hazard assessments in the western United States. Specific emphasis is placed upon free, publicly available toolsdeveloped by the U.S. Geological Survey (USGS) and available for analyses in support of Burned Area Emergency Response (BAER) and Emergency Watershed Protection (EWP) program activities. These tools consist of empirical models that predict the likelihood, potential volume, and the rainfall intensity-duration thresholds for debris flows in recently burned watersheds.