The US road safety regulator has opened a probe into Tesla’s vehicles equipped with full self-driving (FSD) software following a number of incidents, including a fatality.

The National Highway Traffic Safety Administration (NHTSA) received four reports of a crash after a Tesla vehicle entered an area of reduced visibility conditions – such as sun glare, fog, or airborne dust – while the FSD was engaged. One crash resulted in the death of a pedestrian, while another one caused an injury, Kallanish understands.

Authorities will evaluate whether FSD can detect and respond appropriately to reduced visibility conditions, whether any other similar FSD crashes have occurred, and any updates or modifications to the software that may affect its performance.

It comes days after Tesla’s ceo and co-founder Elon Musk unveiled the Cybercab robotaxi and a robovan, two fully autonomous vehicles with no human controls. Musk said FSD will be safer than human driving because Tesla’s fleet collects data much faster than the average person, which allows them to build experience more quickly.

Tesla and other FSD providers, such as Waymo, General Motors and Amazon’s Zoox, are under intense scrutiny following crashes, injuries and fatalities. Yet, Waymo is allowed to operate on public roads in the US, unlike Tesla.

“A vision only self-driving system is severely degraded in poor weather conditions,” says Dan O’Dowd, founder of safety advocacy group The Dawn Project. “All the other robotaxi developers recognised long ago that vision-only systems frequently encounter conditions in which visibility is impaired and have implemented additional sensors such as Radar and Lidar that operate in adverse conditions.”

“NHTSA’s latest probe shows that Elon Musk’s decision to prioritise profits over safety by refusing to use Lidar and Radar in Tesla’s self-driving software is having lethal consequences for road users. Musk has repeatedly criticised his rivals for using these ‘expensive and unnecessary sensors,’” O’Dowd adds.

Tesla was contacted for comment. Shares were flat on Friday following the news.