The National Transportation Safety Board and the Federal Aviation Administration are investigating a plane crash that killed two people off the coast of Half Moon Bay in California Saturday.
According to the NTSB, a Viking Air DHC-6-400 Twin Otter crashed into the Pacific Ocean shortly after declaring a mayday at around 2:15 p.m.
NTSB officials added that the U.S. Coast Guard located the plane submerged about 40 miles off the Northern California coast and confirmed the pilot and copilot suffered fatal injuries.
The FAA said the plane was flying from Santa Rosa to Honolulu, Hawaii.
There were no other passengers on board and investigators are working to recover the plane, an NTSB spokesperson told NBC Bay Area Sunday.
No other details were released.