TORONTO -- Canadian Armed Forces have confirmed the identities of the six crew members who were on board the military helicopter that crashed during a NATO training exercise off the coast of Greece.

During his daily briefing in Ottawa Thursday, Prime Minister Justin Trudeau said that one body has been recovered and five others are missing.

"All of them are heroes. Each of them will leave a void that cannot be filled," he said.

The prime minister was joined by Chief of the Defence Staff Gen. Jonathan Vance who said they had confirmed the death of one sailor, Sub-Lt. Abbigail Cowbrough of Nova Scotia.

“This is a time of agony for all families, friends and fellow crew members. There is nothing worse than sending your shipmates over the horizon and losing contact,” he said.

On Thursday afternoon, the Canadian Armed Forces also confirmed the identities of the five missing crew members:

Capt. Brenden Ian MacDonald from New Glasgow, N.S.

Capt. Kevin Hagen from Nanaimo, B.C.

Capt. Maxime Miron-Morin, from Trois-Rivieres, Que.

Sub-Lt. Matthew Pyke from Truro, N.S.

Master Corp. Matthew Cousins from Guelph, Ont.

Military members on HMCS Fredericton, along with NATO allies, are continuing to search for the other five members of the helicopter's crew.

“Right now, search conditions are good, but we’re now searching a much larger area given the effects of wind and current,” Rear-Admiral Craig Baines told reporters on Thursday afternoon from Halifax. “This search has been going on for some time now -- over 24 hours -- and is absolutely assisted by the terrific work of our allies. They have been absolutely steadfast in supporting Canada in searching for our missing crew members.”

Vance said search efforts have been complicated by a large debris field and the fact the helicopter crashed in 3,000-metre deep water.

Trudeau said the helicopter was flying from Halifax-based naval frigate HMCS Fredericton as part of NATO’s Operation Reassurance. The CH-148 Cyclone lost contact during an allied exercise over the Ionian Sea on Wednesday.

“This is another very hard day for Halifax, for Nova Scotia, and for our Armed Forces families. I am so very sorry for your loss,” he said.

Defence Minister Harjit Sajjan said the cause of the incident is unknown at this time.

“Based on what we know so far, because this was a training exercise and given this is a frigate that has capabilities to know and determine threats, there’s no indication (of foul play),” Sajjan told CTV’s Power Play.

“We will go through a full investigation to make sure that we answer all the questions, (but) not rule anything out.”

He said the voice and data recorders that broke away from the helicopter during the crash had been recovered and would be transported back to Canada for the investigation.

“It’s really important for us to get the investigators on the ground to determine what has gone on,” Sajjan said. “We’ll get to the bottom of this and we’ll make sure the families are kept fully in the loop.”

Additionally, a flight safety team from the Royal Canadian Air Force will be leaving Canada this week to investigate the crash.

“I wish to express my deepest condolences to their families, friends, and colleagues,” Sajjan said in a statement.

“This accident is a painful reminder of the dangers that members of Canada’s military face every day to ensure the safety and security of Canadians.”

Vance said approximately 240 CAF members who left Halifax in January, to take part in NATO’s Operation Reassurance, had just completed their 100th day of the mission. They are expected to return to Canada in July.

According to NATO, HMCS Fredericton recently sailed from Souda, Greece to continue with its mission of “maritime situational awareness” in the Mediterranean.

The ship had been a unit of Standing NATO Maritime Group Two (SNMG2) and had performed several exercises with units of the Turkish Navy and the Hellenic Navy and Air Force this past week, NATO said in a statement Thursday.

Prior to that, the ship visited Italy in March, before it was to travel to Greece and the Black Sea as one of eight warships in SNMG2.

Baines said that the plan is for HMCS Fredericton to remain part of Operation Reassurance for the duration of the mission.

The helicopter carrying six CAF members had just completed a training exercise with Italian and Turkish warships and was flying back to the ship when it lost contact at approximately 6:52 p.m. local time on Wednesday, Vance said. He didn’t say whether there had been a mayday call, but the data and voice recorders were lit up automatically by flares when they broke off the helicopter.

As a result of the crash, Vance said the Cyclone helicopter fleet was on an “operational pause” to allow flight safety teams to investigate and rule out any potential fleet-wide problems. The Royal Canadian Air Force owns 17 other Cyclone helicopters.

Baines said the operational pause will remain in place for as long as needed for the Air Force investigation to take place.

Trudeau said NATO Secretary General Stoltenberg offered his condolences when they spoke earlier on Thursday.

Greek Prime Minister, Kyriakos Mitsotakis, also shared his condolences.

“I express my grief over the crash of the Canadian helicopter in the Ionian Sea last night,” he told parliament on Thursday.

Mitsotakis added that he intended to call Trudeau to extend his sympathies.

The Canadian military only began using Cyclone helicopters for missions in late 2018 after more than a decade of expensive delays with the manufacturer Sikorsky. In 2008, the military was supposed to receive 28 Cyclone helicopters, to replace its aging CH-124 Sea Kings, but they only have 18 of the helicopters to date.

When asked if he had any concerns about the fleet, Vance defended the helicopters’ performance.

“It’s a powerful helicopter with fantastic sensing capability,” he said. “I don’t have any lack of confidence in this fleet.”

Cowbrough’s family ‘broken and gutted’

Earlier on Thursday, the family of the first victim identified in the crash, Sub-Lt. Abbigail Cowbrough, shared news of her death on social media.

In a Facebook post, Shane Cowbrough confirmed that his daughter Abbigail was among the victims.

“I am broken and gutted,” he wrote. “There are no words. You made me forever proud. I will love you always, and miss you in every moment. You are the bright light in my life taken far too soon.”

Tanya Cowbrough, Abbigail’s mother, also shared the devastating news on her Facebook page.

“My beautiful daughter has been in a military accident and passed away. She will no longer pipe her songs to all those that love her,” she wrote. "The very beating no fluttering of my heart has stopped. Nothing can replace her.”

The Regal Heights Baptist Church in Dartmouth, N.S. posted about Abbigail Cowbrough’s death in a Facebook post early Thursday morning.

“Our church family has lost a wonderful woman,” the post read. “Our prayers are with her family, and all those who have lost a loved one in this tragic accident.”

The church also shared two photos of Cowbrough. In one, she can be seen playing the bagpipes during a Remembrance Day ceremony in Dartmouth last year. The other photo shows Cowbrough aboard HMCS Fredericton, which she sent to the church to show them where she was spending quarantine during the pandemic.

The young woman was known as a talented bagpiper who played for the Halifax Regional Fire Service’s Union Fire Club Pipes and Drums band. In a Facebook post Thursday, the band said they were “profoundly saddened” by her death.

“She was an amazing person and loved by all who met her. Abbi thank you for joining our little band and making it better. See you on the counter march!”

With files from CTV News’ Michel Boyer and The Canadian Press