Two persons were killed in an aircraft accident northwest of San Francisco’s Golden Gate Bridge on Friday afternoon, according to the Marin County Sheriff’s Office.

According to the announcement, the plane, a fixed-wing, single-engine Vans RV-10 personal aircraft, crashed into a slope near Slacker Hill in the Marin Headlands. It said that the emergency beacon on the plane was triggered roughly two minutes later.

The sheriff’s office reported that “heavy fog and mist obstructed vision in the region,” making it difficult for first responders to locate the jet. The plane was discovered at 2 p.m., and the two passengers on board were pronounced dead on the spot.

The identity of the victims will be revealed on Monday, according to the sheriff’s office.

The National Park Service, the Federal Aviation Administration, the National Transportation Safety Board, and the sheriff’s office will all examine the collision, according to the statement. The cause and manner of death will not be revealed until the inquiry is completed.

The sheriff’s office has ordered a postmortem toxicology examination for early this week.