A mid‑afternoon fire inside a Pacific Gas & Electric substation sent large swaths of San Francisco dark on Saturday and, for a while, brought a glimpse of the gaps in a future city crowded with driverless cars.
Videos that flooded social media showed Waymo’s fully driverless taxis stopped in intersections and hesitating at darkened traffic lights. By evening Waymo said it had “temporarily suspended” its ride‑hailing service in the Bay Area while it worked with city officials to ensure rider and public safety.
A city goes dark, transit grinds
Pacific Gas & Electric reported the outage began shortly after 1 p.m. and at its peak affected about 130,000 customers — roughly one‑third of the utility’s San Francisco customers. Fire crews said the trouble started with smoke and flames inside a substation at 8th and Mission; PG&E described the damage as “significant and extensive.”
The blackout knocked out streetlights and traffic signals across the northwestern part of the city. San Francisco’s emergency office urged people to avoid nonessential travel and treat dark intersections as four‑way stops. Muni rerouted and bypassed some underground stops; BART skipped Civic Center and Powell for a time. Mayor Daniel Lurie said police, parking control officers and fire crews were deployed across affected neighborhoods to help transit and pedestrian flow.
By late night PG&E had restored power to most customers; company trackers showed roughly 20,000–25,000 people remained without electricity early Sunday as crews assessed and repaired damage.
When cars expect signals that aren’t there
Waymo’s driverless vehicles rely on high‑definition maps, sensors and visible infrastructure cues — like traffic lights — to make decisions. When signals went dark and intersections reverted to ad‑hoc traffic control, some Waymo cars reportedly stalled or paused, creating congested spots and prompting the company to halt service until conditions stabilized.
That failure was jarring because it’s precisely the sort of disruption planners have warned could trip up robotic systems. Bryan Reimer, a research scientist at MIT’s Center for Transportation, told reporters that blackouts are predictable hazards and that fleets of highly automated vehicles need human backup systems and operational plans for such events.
The incident also drew a cheeky response from Tesla CEO Elon Musk, who posted that “Tesla Robotaxis were unaffected by the SF power outage.” While Tesla operates ride‑hail offerings in some areas using cars with its FSD (Supervised) package, state regulators note Tesla does not run truly driverless, unsupervised robotaxis in California; its services currently include a human behind the wheel in places where permits require one.
Bigger questions about deployment and resilience
The outage highlighted two thorny threads about putting more autonomous vehicles on city streets. First: how should driverless systems behave when civic infrastructure fails? And second: who is accountable when automated fleets contribute to confusion or gridlock during emergencies?
City and state regulators that oversee permits and public safety will likely revisit how much penetration highly automated vehicles can have in urban cores, and what operational requirements — from remote human supervisors to fallback routing — should be mandatory. The episode also underscores the technical dependence AVs have on external signals and detailed map data; advances in navigation and on‑device reasoning could help, but they aren’t a panacea. For perspective on how navigation AI is evolving, see how Google Maps' Gemini copilot aims to bring more conversational, context‑aware routing to users.
There’s also a broader AI infrastructure conversation underway about where compute and data live and how systems stay robust under stress — a theme that feeds into services beyond navigation, including enterprise search and document tools (Gemini Deep Research being a recent example of AI moving deeper into everyday apps).
The human cost of an outage
Beyond the tech policy debate, the blackout hit businesses and holiday shoppers during a busy weekend. Theaters, restaurants and shops closed when lights and payment systems failed; transit disruptions left commuters stranded or rerouted; holiday decorations and streetlights that usually brighten the city were dark for hours.
PG&E said crews were mobilized overnight and that there were no injuries reported related to the substation fire. Investigations into the cause and into the full timeline for restoration were ongoing.
This episode won’t settle the debate about robotaxis one way or another, but it does offer a blunt reminder: cities and the automated systems moving through them must be designed to survive the ordinary shocks of urban life — from fires to power failures — without turning a localized problem into citywide chaos.