SAN DIEGO — A plane crash in San Diego that killed six people, including groundbreaking alternative music executive Dave Shapiro, happened as the private plane approached an airport whose runway lights were out in heavy fog, investigators said.

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 into a neighborhood, NTSB officials said Friday, adding that they haven’t yet determined the cause of the crash.