NHTSA’s Office of Defects Investigation (ODI) is aware of two incidents occurring on US public highways in which a Model S caught fire after an undercarriage strike with metallic roadway debris; the resulting impact damage to the propulsion battery tray (baseplate) initiated thermal runaway, NHTSA said.

In each incident, the vehicle’s battery monitoring system provided escalating visible and audible warnings, allowing the driver to execute a controlled stop and exit the vehicle before the battery emitted smoke and fire.