The wreckage is seen after a small plane crashes in the waters off Half Moon Bay on January 15, 2024 in San Mateo County, California. A woman's body was found near the plane crash site.China News Service via Getty ImagesA homebuilt aircraft crashed into the ocean just south of San Francisco on Sunday.Four people were reportedly on board the flight when it went down.The retired dentist who built the plane called the incident "traumatic."A small homebuilt aircraft crashed off the coast of California on Sunday, The Associated Press reported.Federal investigators said they believed four people had been traveling in the single-engine Cozy Mark IV when it crashed at Half Moon Bay, just south of San Francisco.No survivors were found and just one body had been discovered as of Friday.While no official cause has been given for the crash, a witness said that they had heard the plane's engine cut out after losing power, per The AP.In a post on Facebook, the San Mateo County Sheriff's Office said: "Authorities responded to reports of a small airplane flying erratically near Moss Beach, CA.""A Coast Guard helicopter and a CHP fixed wing plane were deployed to assist.