The weather alert system and runway lights weren’t working at a foggy San Diego airport where a private jet was planning to land before it crashed.That’s according to Dan Baker of the National Transportation Safety Board.

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.