The runway lights were out, a weather alert system wasn’t working and there was heavy fog at a San Diego airport when a pilot who had flown across the country made the decision to proceed with landing but came up short and crashed into a neighborhood.

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.

During a news conference Friday, an NTSB investigator said a technical glitch at Montgomery-Gibbs Executive Airport knocked out a system that gives weather updates to approaching pilots.