WASHINGTON — California firefighters had to spray about 50,000 gallons of water on a burning battery on a Tesla electric truck to extinguish the fire following a crash, the National Transportation Safety Board (NTSB) said Thursday.
In addition to the massive amount of water, firefighters used an aircraft to drop fire retardant in the “immediate area” of the Tesla Semi as a precaution, the agency said in a preliminary report.
Fire officials previously said the battery reached temperatures of 1,000 degrees Fahrenheit while it was on fire.
The NTSB sent investigators to the Aug. 19 crash on Interstate 80 near Emigrant Gap, about 70 miles northeast of Sacramento. The agency said it would look into fire risks posed by the truck’s large lithium-ion battery.
The agency also found that the truck was not operating one of Tesla’s partially automated driving systems at the time of the crash, the report said. The systems were not operational and “could not be activated,” according to the agency.
The crash happened around 3:13 a.m., when a Tesla employee was driving the tractor-trailer from Livermore, California, to a company facility in Sparks, Nevada. The semi-trailer veered off the road while negotiating a right-hand curve and struck a tree, according to the report. It went down a slope and came to rest against several trees. The driver was not injured.
After the crash, the truck’s lithium-ion battery caught fire. Firefighters used water to extinguish the flames and keep the batteries cool. The highway was closed for about 15 hours while firefighters made sure the batteries were cool enough to recover the truck.
Authorities took the truck to an outdoor facility and monitored it for 24 hours. The battery never came back on.
The NTSB said all aspects of the accident are under investigation while the cause is determined. The agency said it intends to issue safety recommendations to prevent similar incidents.
A message seeking comment was left Thursday with Tesla, which is based in Austin, Texas.
Following an investigation that concluded in 2021, the NTSB determined that high-voltage EV battery fires pose risks to first responders and that manufacturers’ guidelines on how to address them were inadequate.
The agency, which has no enforcement powers and can only make recommendations, asked manufacturers to write vehicle-specific response guides to combat battery fires and limit chemical thermal runaway and reignition. The guidelines should also include information on how to safely store vehicles with damaged lithium-ion batteries, the agency said.
Tesla began delivering the electric trucks in December 2022, more than three years after Chief Executive Elon Musk said his company would start making them. Musk has said the Tesla Semi has a range per charge of 500 miles when towing an 82,000-pound load.
