A bus carrying Tesla employees crashed into a vehicle on a California highway Friday morning, killing an off-duty law enforcement officer, police said.

The bus, which was carrying more than 50 employees of the electric car company, was driving on a freeway east of the Tesla factory in Fremont when it rear-ended a Volkswagen Beetle around 7am, crushing the car and killing the driver, according to the California Highway Patrol (CHP).

One passenger on the bus suffered minor injuries but was treated on the scene, said CHP spokesman Derek Reed. The bus was contracted by Tesla and was driving to Stockton, a city 50 miles east of the company’s main facility in Fremont.

“We are aware of an accident this morning involving an independently-operated shuttle carrying Tesla employees and another vehicle,” the company said in a statement. “All Tesla employees on the bus are safe and accounted for, however we are deeply saddened by reports that there was a fatality as a result of the accident. We will lend any support that we can to the authorities who are investigating the incident.”

The VW Beetle came to a stop on the highway, and because of the glare from the sun, the bus driver was not able to see the car, according to Reed.

“The vehicle was crushed and the driver was trapped inside, and he passed away on the scene,” he said, adding that it was unclear why the car had stopped.

The luxury car company is one of many corporations developing self-driving vehicle technology in Silicon Valley, and CEO Elon Musk has argued that autonomous driving will dramatically reduce traffic collisions.

Tesla experienced its first fatal crash while one of its drivers was using the autopilot mode last year. The sensors on the Model S failed to distinguish a white tractor-trailer crossing the highway against a bright sky. The company deflected blame for the crash, noting that the car’s autonomous software is designed to direct consumers to keep their hands on the wheels and continue to pay attention to the road.

Footage from the scene of the crash on Friday, which happened in the city of Livermore, showed CHP officers gathering around the body, saluting and draping an American flag over the deceased officer, according to local station NBC Bay Area.

CHP did not immediately release the name of the officer or identify the individual’s police agency.

Shuttles carrying tech employees have become increasingly common and controversial in San Francisco and the surrounding area where some critics have said the buses have helped accelerate gentrification and provide a luxury private transit system that has caused major problems at public bus stops.

The purpose of the bus travel on Friday morning was not immediately clear. Tesla has property in Lathrop, a town near Stockton. A company spokesperson did not respond to a request for comment about the destination of the bus.