The crash happened at the intersection of Turk and Polk in the city's Tenderloin district after 10 p.m. The incident was immediately called in: "Yeah, can you dispatch a battalion chief? We've been involved in an accident versus a Cruise vehicle. There was one person in the vehicle."
As seen in multiples videos, the firetruck was apparently headed southbound but had moved into the northbound lane, something trucks do to get around other cars.