The Brief A small plane made an emergency landing on Interstate 15 in San Diego this afternoon, landing on the center divider. The incident, which occurred just before 5 p.m. near the Balboa Avenue exit, caused traffic delays but resulted in no injuries. The cause of the emergency landing is currently unknown and is under investigation. A small plane safely landed on Interstate 15 in San Diego Monday afternoon during the evening rush hour commute. What we don't know:The cause of the emergency landing is under investigation.