Prime Minister Justin Trudeau says six people were aboard the Canadian Forces helicopter that crashed off Greece during a training exercise.
One body has been recovered and five remain missing after the Cyclone helicopter went down, he says.
The helicopter was flying a mission from HMCS Fredericton, a Canadian frigate taking part in a NATO mission.
In a briefing in Ottawa, chief of the defence staff Gen. Jonathan Vance says the one sailor confirmed to have died is Sub-Lt. Abbigail Cowbrough of Nova Scotia.
Vance says there's nothing worse than seeing fellow service members go over the horizon and losing contact with them.
Multiple NATO countries are in an ongoing search-and-rescue operation in the Ionian Sea, hoping to find survivors.
The flight data recorders have been recovered, after they broke off from the aircraft and floated to the surface. The recorders were able to be found thanks to a tracking beacon.
The wreckage is believed to be in about 3,000 meters of water.
The Canadian Armed Forces has identified the five service members missing in Wednesday's helicopter crash off the coast of Greece.
The government earlier today confirmed that Sub-Lt. Abbigail Cowbrough died when the Cyclone helicopter crashed.
Those missing are:
Capt. Brenden Ian MacDonald, one of the Cyclone helicopter's pilots. He is originally from New Glasgow, N.S.
Capt. Kevin Hagen, the Cyclone's other pilot. He is originally from Nanaimo, B.C.
Capt. Maxime Miron-Morin, an air combat systems officer, originally from Trois-Rivieres, Que.
Sub-Lt. Matthew Pyke, naval weapons officer, originally from Truro, N.S.
Master Cpl. Matthew Cousins, airborne electronic sensor operator, originally from Guelph, Ont.