On the morning of April 21, 2026, a Tesla vehicle traveling northbound on Interstate 280 in Daly City collided with a guardrail near the Serramonte Boulevard exit, triggering a significant battery fire. The California Highway Patrol (CHP) reported that the accident occurred at approximately 9:45 a.m. local time. The impact compromised the vehicle's undercarriage, where the lithium-ion battery pack is located, leading to a thermal runaway event. No other vehicles were involved in the initial collision, and the driver was able to exit the vehicle without sustaining life-threatening injuries.
The North County Fire Authority arrived on the scene shortly after the collision to find the vehicle fully engulfed in flames. Firefighters encountered challenges common to electric vehicle fires, which burn at higher temperatures and can reignite hours after the visible flames are extinguished. According to Battalion Chief Mark Henderson, crews utilized thousands of gallons of water to cool the battery cells directly. The CHP issued a SigAlert at 10:15 a.m., shutting down all northbound lanes of I-280 to provide a safety perimeter and allow for the staging of specialized hazardous materials equipment.
Tesla’s emergency response guide for first responders notes that battery fires can take up to 24 hours to fully extinguish and may require between 3,000 and 8,000 gallons of water applied directly to the battery. In this instance, the North County Fire Authority coordinated with San Mateo County’s hazardous materials team to monitor runoff and ensure that the damaged battery pack was safely contained for transport. The vehicle was eventually moved to a secure storage lot, where it will remain under observation for 48 hours to prevent potential reignition, a standard protocol for high-voltage battery incidents.
The closure of the northbound lanes lasted for approximately five hours, with traffic diverted onto State Route 1 and local Daly City streets. The California Department of Transportation (Caltrans) was dispatched to inspect the guardrail and the road surface, which sustained heat damage from the intensity of the fire. By 3:30 p.m., two lanes were reopened to traffic, though residual delays stretched back several miles into San Bruno. Tesla has not issued a formal statement regarding the specific vehicle model involved or the cause of the initial collision as of Tuesday afternoon.
This incident follows ongoing discussions between the National Highway Traffic Safety Administration (NHTSA) and electric vehicle manufacturers regarding the structural integrity of battery casings during side-impact and guardrail collisions. While electric vehicle fires are statistically less frequent than internal combustion engine fires per mile driven, the logistical complexity of extinguishing them remains a focal point for municipal fire departments. The Daly City incident will likely be documented in the NHTSA’s ongoing safety data collection for alternative fuel vehicles.