DETROIT (AP) — The U.S. government's road safety agency has dispatched a team to investigate the possibility that a Tesla involved in a California crash that killed three people was operating on a partially automated driving system.

The National Highway Traffic Safety Administration on Wednesday confirmed that it had sent a special crash investigation team to probe the May 12 crash on the Pacific Coast Highway in Newport Beach.

The investigation is part of a larger inquiry by the agency into crashes involving advanced driver assistance systems such as Tesla's Autopilot. Since 2016, the agency has sent teams to 34 crashes in which the systems were either in use or suspected of operating. Of the 34, 28 involved Teslas, according to a NHTSA document released Wednesday.

Fifteen people died in the crashes that NHTSA is investigating, and at least 15 more were hurt. Of the deaths, 14 occurred in crashes involving Teslas, the documents say.

In addition to the specific crashes, NHTSA has investigations under way into Teslas on Autopilot crashing into emergency vehicles parked along roadways, as well as a probe into Autopilot braking for no apparent reason.

Last June NHTSA or dered automakers to report any crashes on public roads involving fully autonomous vehicles or those with partially automated driver assist systems. The partially automated systems can keep a vehicle centered in its lane and a safe distance from vehicles in front of it. NHTSA says the data can show if there are common patterns in crashes involving the systems.

A message was left Wednesday seeking comment from Tesla, which is headquartered in Austin, Texas. NHTSA wouldn't comment beyond release of the document.

Tesla warns drivers using Autopilot, as well as its "Full Self-Driving" system, that the cars can't drive themselves and that drivers must be ready to intervene at all times.

NHTSA also is investigating two crashes involving Volvos, one Navya shuttle crash, two involving Cadillacs, one in a Lexus and one in a Hyundai. One of the Volvo crashes was an Uber autonomous test vehicle that ran over and killed an Arizona pedestrian in March of 2018.

In the Newport Beach crash, police were called around 12:45 a.m. and found that a 2022 Tesla Model S sedan had crashed into a curb and then hit construction equipment on the south side of the road.

Authorities found two men and a woman dead in the car, and three construction workers suffered minor injuries, according to police.

The Newport Beach Police Department said it brought in its Major Accident Investigation Team.