Assessing Structure Collapse and Vegetation Loss After the 2025 Eaton Fire Using Optical Remote Sensing

Abstract On 7–8 January, 2025, the Eaton fire destroyed >9,000 structures and >40 km 2 of forest in the northeastern region of the Los Angeles metropolitan area, California. Building damage was primarily assessed through ground investigations, a process that took several weeks due to hazardous conditions and the difficulty of accessing burnt areas. This study presents a novel approach for post‐disaster damage assessment using sub‐meter resolution satellite optical imagery. The Eaton fire is a good test case study as it benefits from ground‐truth data collected during field surveys and subsequent airborne LiDAR acquisitions. The proposed approach utilizes stereo pairs of optical satellite images to reconstruct the 3D ground surface geometry before and after the event, enabling the detection of elevation changes across the affected regions. Results reveal meter‐scale elevation differences associated with both collapsed structures and burned vegetation, spanning urban areas and the adjacent Angeles National Forest. This technique leverages established photogrammetric and post‐processing methods, making it reproducible and adaptable to various disasters and geographic areas. The ultimate goal is to offer a rapid, high‐resolution satellite‐based solution for damage mapping.