The U.S. National Highway Traffic Safety Administration (NHTSA) is investigating Tesla (TSLA  ) after several reports of the company's vehicles colliding with emergency vehicles while the Autopilot system was engaged. The investigation covers nearly every Tesla sold in the U.S. since 2014, or roughly 765,000 vehicles.

The investigation covers Tesla Models Y, X, S, and 3 from the years 2014 to 2021.

While the probe doesn't cover all of them, the NHTSA has sent investigators to 31 Tesla crashes since 2016. Of those crashes, 25 included the use of the Tesla Autopilot, with those incidents resulting in 10 deaths overall.

The probe will focus on 11 incidents since 2018 that overall contributed to the death of one individual and the injury of another 17.

Each of these incidents involved a Tesla vehicle on Autopilot colliding with emergency and first responder vehicles. The crashes occurred while the emergency vehicles were marked using a combination of flairs, flashing lights, arrow boards, and other hazard signs.

The NHTSA isn't the only agency to investigate claims regarding Tesla's Autopilot. The National Transportation Safety Board (NTSB) has no enforcement power but has recommended that the NHTSA and Tesla carry out two changes.

First, the board recommends limiting the use of Autopilot to those areas where it can be used safely. Second, the board recommends the NHTSA force Tesla to improve the safety systems in place that keep drivers paying attention to the road while Autopilot is in operation. So far, the NHTSA has not acted on any of the NTSB's recommendations.

However, the probe itself is a sign that the Biden Administration will be taking the alleged potential risks of automated vehicles, Tesla's Autopilot included, more seriously than the prior administration. Previously, the government was concerned that enforcing safety rules over auto companies could stifle progress on these new systems.

NHTSA's inaction caused the NTSB to attribute part of the blame for two Tesla accidents to the agency, including one accident in 2019 in which a driver was killed when neither he nor the vehicle's Autopilot system braked or swerved to stop the Tesla Model 3 from driving straight into a tractor-trailer crossing the vehicle's path.

Cases in which Tesla drivers crash due to an assumption that the Tesla Autopilot system is fully automated are all too common. The Autopilot is meant to keep the vehicle in the lane and at a safe following distance to other vehicles in front of it, meaning that drivers should still monitor the road at all times to make sure that no unexpected obstacles, like emergency vehicles and tractors, arise without notice.

Unfortunately, drivers have been found drinking and driving as well as riding in the back seat of the vehicle while the Autopilot was engaged. There are also stories of Tesla owners sleeping while driving, with one Canadian man being caught traveling at over 90 mph while asleep in his Tesla

"Although manufacturers of new vehicles have built-in safeguards to prevent drivers from taking advantage of the new safety systems in vehicles, those systems are just that - supplemental safety systems," an Alberta official said in a statement. "They are not self-driving systems, they still come with the responsibility of driving."

According to automated-vehicle expert at Carnegie Mellon University, Professor Raj Rajkumar, this investigation into Tesla should have happened a long time ago. He argues that the NHTSA should focus on Tesla's failure to ensure that drivers are paying attention to the road. While there are systems in place, they are reportedly a minor hindrance.

"It's very easy to bypass the steering pressure thing," Rajkumar told NPR. "It's been going on since 2014. We have been discussing this for a long time now."

Rajkumar also stated that Tesla's test runs of its so-called "full self-driving" vehicles by select owners should be investigated.

Based on the NHTSA's investigation documentation, driver inattention does seem to be their first priority, though they are also expected to investigate Tesla's event detection system and its range of operability.

"The investigation will assess the technologies and methods used to monitor, assist and enforce the driver's engagement with the dynamic driving task during Autopilot operation," wrote the NHTSA.

The NHTSA has stated that it can use its "robust enforcement tools" to investigate and address safety issues if it finds any proof "of noncompliance or an unreasonable risk to safety."

Following the opening bell on the day of the NHTSA's announcement, Tesla shares fell by 3.5%.