On Saturday, San Francisco experienced a significant power outage, impacting around 130,000 customers at its height, as reported by Pacific Gas and Electric Company. This blackout also led to another complication: immobilized Waymo vehicles. Social media was abuzz with images and videos of the company’s autonomous SUVs halted in the streets, contributing to traffic congestion.

Amidst the chaos, some social media users shared clips of Teslas successfully navigating the same streets utilizing their Full Self-Driving (FSD) feature. Elon Musk chimed in on Twitter, noting that “Tesla Robotaxis remained unaffected by the SF power outage.”

Responding to a query from The Verge, Waymo spokesperson Suzanne Philion explained, “We have temporarily suspended our ride-hailing services due to the widespread power outage in San Francisco. Our priority is ensuring the safety of our passengers and providing emergency personnel with the necessary access to perform their duties.” By 7 AM PT, PG&E had restored power to approximately 110,000 customers and was working to reconnect the remaining 21,000, primarily in areas like the Presidio, Richmond District, Golden Gate Park, and parts of downtown San Francisco, following a fire at a five-story power substation.

The exact reason for the Waymo vehicles’ standstill remains unclear, with no public updates available on the company’s social media channels. Theories suggest unreliable wireless data connections, as cell towers were either down or overwhelmed by users lacking Wi-Fi access, and non-functioning traffic signals due to the outage.

Such challenges are not new for Waymo. Earlier TikTok videos depict similar scenarios where Waymos were immobilized by a malfunctioning traffic light and during a blackout in Austin, Texas. On Reddit, a user claiming to be a former employee explained that the vehicles would seek assistance from a remote operator and await instructions before proceeding.

According to a Waymo blog post, the vehicles contact a human response agent when encountering “unique interactions,” providing them with live and recorded footage from its cameras and a 3D map of sensor data. However, such interactions require bandwidth, which can be scarce amid a major power outage. While statistics on the number of remote assistance operators Waymo employs at any time are unavailable, the company announced in November that it passed a third-party audit by Tüv Süd, a German tech inspection firm, which evaluated its remote assistance program against industry standards.