To the Editor Dr Basu and colleagues provided a national estimate of mortality in US Immigration and Customs Enforcement (ICE) detention for fiscal years 2004 through 2026. They conducted a retrospective, repeated cross-sectional descriptive analysis using public and official data. This approach estimates annual mortality rates but cannot establish causality or identify facility-level, clinical, or policy-related drivers of the recent increase. Their report of 272 deaths, rising mortality rates, and frequent other or undetermined causes highlights a central limitation that surveillance can count deaths but often cannot explain them.