(CNN)A plane crash northwest of San Francisco's Golden Gate Bridge on Friday afternoon killed two people, the Marin County Sheriff's Office said in a news release.
The plane -- identified as a fixed-wing, single-engine Vans RV-10 personal aircraft -- crashed into a hillside in the Marin Headlands near Slacker Hill, said the release. The aircraft's emergency beacon was activated about two minutes later, it added.
First responders deployed to search for the plane, but their efforts were hindered by "heavy fog and condensation, which obscured visibility in the area," the sheriff's office said. The plane was found at about 2 p.m., and the two people inside were declared dead at the scene.
The victims' identities will be released Monday, the sheriff's office said on Twitter.
The crash will be investigated by the National Park Service, the Federal Aviation Administration, the National Transportation Safety Board and the sheriff's office, it said. Cause and manner of death will not be released until the conclusion of the investigation.
A postmortem toxicology examination is scheduled for early this week, the sheriff's office said.