Coast Guard spokeswoman Loumania Stewart says a water search is underway after debris was spotted in San Pablo Bay following the Sunday afternoon collision.
Federal Aviation Administration spokesman Ian Gregor says the collision off the city of Richmond involved a Cessna 210 and a Hawker Sea Fury TMK 20. Each aircraft had one person on board.
He says the Cessna crashed into the water and the pilot of the Hawker was able to land safely at a small airport in Northern California. The pilot was reportedly uninjured.