https://www.cnet.com/news/uber-finds-that-a-software-problem-likely-led-to-deadly-accident-in-march/

Uber has reportedly found that a software problem likely caused a fatal accident involving one of its self-driving cars in Arizona in March. That software is meant to determine how the car should react to detected objects, two people familiar with the matter told The Information. 

Although the car's sensors detected the pedestrian, Uber's software determined that it didn't need to immediately react because of how it was tuned.