Los Angeles County Sheriff's authorities were en route to the scene to investigate. L.A. County Fire was also notified.
Sheriff's Air Rescue was in the middle of another rescue, and could not immediately respond to the mid-air crash report.
Sheriff's Dept. and County Fire Dept. helicopters were dispatched to the crash.
A pilot reported the accident to the FAA. FAA authorities are looking for a debris field. The incident is now reportedly a search-and-rescue mission. Coast Guard cutters are part of the search.