Dense fog had rolled into the area around the time the plane was approaching the airport. Visibility was at half a mile at 3:55 a.m. and had dropped to a quarter of a mile just after 4 a.m. in the area around Marine Corps Air Station Miramar, which is just a few miles north of the crash site, according to the National Weather Service.

The music agency Sound Talent Group said Thursday that three of its employees, including co-founder Dave Shapiro, died on the private plane that crashed into a San Diego neighborhood early that morning.