Overview
- USGS recorded the main shock at 9:49 p.m. about nine miles northwest of Susanville in Lassen County.
- A magnitude 2.5 aftershock occurred roughly 10 minutes later in the same area.
- Exposure estimates indicate about 2.3 million people felt intensity II or higher, with the strongest shaking at MMI VI affecting roughly 30 people.
- Emergency alerts reached some Northern California phones instructing residents to drop, cover, and hold on.
- Officials reported no immediate widespread damage and flagged potential secondary hazards such as landslides and liquefaction, noting vulnerabilities in unreinforced and reinforced masonry buildings.