The robots continue to learn and show us what they don't understand, and this week brings news of another type of emergency situation that a Zoox vehicle failed to safely navigate around.

Zoox, Amazon's self-driving car subsidiary, voluntarily recalled all of its autonomous vehicles earlier this month, as KRON4 reports, following a dangerous June 20 incident in which a Zoox vehicle apparently drove into an emergency fire scene that was obscured by smoke.

KRON4 obtained the safety recall report from the National Highway Traffic Safety Administration, which describes the problem as "The ADS [Automatic Driving Systems] software may fail to detect heavy smoke, allowing the vehicle to enter an area of low visibility, particularly active emergency scenes."

The Zoox vehicle reportedly "encountered heavy smoke that obscured an active emergency fire scene that was not cordoned off with cones. The Zoox vehicle entered the scene, then braked hard while attempting to steer away before coming to a stop." A Zoox employee then had to remotely navigate the vehicle out of the area.

The report does not say where the fire emergency occurred, but the San Francisco Fire Department was on the scene of a fire in a detached garage on an alley in the Mission District on June 20. Zoox currently only operates in San Francisco and Las Vegas.

This recall follows a similar situation involving Waymo vehicles and emergency situations of several kinds.

Waymo recalled nearly 3,900 of its vehicles last month, stemming from more than a dozen incidents in California and Arizona in which Waymos failed to recognize active freeway construction zones or ramp closures, which also caused Waymo to temporarily suspend freeway service.

Such software recalls typically only require a brief pause in service while the companies push out wireless, "over-the-air" (OTA) software updates for the vehicles' Automated Driving Systems.

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