A hazardous lithium-ion battery fire at a Metropolitan Water District of Southern California facility in La Verne prompted evacuation orders, school safety measures and a major emergency response on Tuesday, September 22, 2026. The fire broke out at a battery energy storage system near a solar panel field at the facility on Wheeler Avenue, creating concerns about smoke, heat and the possibility of additional battery ignition.
According to the latest reports, firefighters were dispatched at approximately 11:40 a.m. after the fire was reported at the facility. La Verne and Los Angeles County firefighters responded, and officials said a significant explosion occurred as crews arrived. The incident involved a battery storage unit located on the northeast side of the property, which also houses the F.E. Weymouth Water Treatment Plant.
One person suffered minor injuries during the incident and was transported to a local hospital for treatment. Officials said the individual was in good condition. No firefighters were reported injured. Authorities continued to monitor the facility because lithium-ion batteries can remain hazardous even after visible flames have been reduced.
The fire prompted evacuation orders for residents near Wheeler and Bonita avenues. People in affected areas were instructed to leave immediately and follow directions from emergency personnel. Residents east of Wheeler Avenue were also told to shelter in place, close windows and doors, and remain indoors while firefighters worked to control the situation.
Nearby schools were affected by the emergency. Shelter-in-place measures were issued at Grace Miller Elementary School and Bonita High School, while students were later released. The University of La Verne also canceled classes and instructed students, faculty and staff to leave campus. Local businesses and roads were also affected as authorities established safety perimeters around the fire scene.
The City of La Verne later reduced the evacuation area as firefighters gained greater control of the damaged battery unit. However, officials maintained an evacuation order around the immediate area of the facility because another battery storage unit had been exposed to heat and remained under observation. The city said the second unit showed signs requiring continued monitoring.
Fire officials explained that lithium-ion battery incidents can be particularly difficult because damaged cells may undergo thermal runaway, a process in which increasing temperatures trigger a chain reaction among battery cells. Even after flames are suppressed, firefighters may need to continue cooling and monitoring the equipment because batteries can potentially reignite.
Crews used water to cool the affected battery equipment while hazardous-materials personnel and air-quality officials monitored conditions. Authorities were also watching smoke and water runoff as part of the emergency response. The Metropolitan Water District said the incident did not affect the safety or operation of the region's water supply.
The cause of the fire had not been publicly established in the latest reports. Investigators and emergency officials continued assessing the facility while crews remained on scene to monitor the battery systems and address any renewed activity.
The City of La Verne advised residents to continue following official emergency instructions and not return to areas that remained under evacuation orders. As conditions improved, portions of the evacuation area were downgraded or reopened, but authorities continued treating the immediate facility area as hazardous while monitoring the remaining battery equipment.
The incident highlights the challenges emergency crews face when responding to fires involving large lithium-ion battery storage systems. For residents affected by the La Verne evacuation, the priority remained safety, compliance with emergency instructions and waiting for authorities to confirm when it was safe to return.