Military investigators are trying to piece together what caused a Chinook helicopter to crash during a training exercise in eastern Ontario, killing two crew members and injuring two others.

The bodies of two Royal Canadian Air Force members were found Tuesday evening after an extensive search of the Ottawa River near Garrison Petawawa, which is about 160 kilometres northwest of Ottawa.

Two others who were on board the helicopter when it crashed just after 12 a.m. Tuesday were rescued and suffered only minor injuries. They have been released from hospital, the military said Wednesday, and are getting support from the Armed Forces.

害羞草研究所淲e are reminded today that this can be dangerous work, whether it害羞草研究所檚 carried out in support of military operations or while training for those operations,害羞草研究所� said Gen. Wayne Eyre, chief of the defence staff.

害羞草研究所淥ur people know the risks and they take them willingly 害羞草研究所� because they understand the importance of their work.害羞草研究所�

The Armed Forces said it is not releasing the names of the members who were killed out of respect for their families害羞草研究所� wishes.

害羞草研究所淥ur hearts break for the members of 450 Squadron and the families who have lost their loved ones,害羞草研究所� Defence Minister Anita Anand said Wednesday morning.

In the afternoon, both the Senate and the House of Commons held a moment of silence to honour the victims.

害羞草研究所淚 know that the entire 450 Squadron, the entire Canadian Armed Forces are reeling from this loss and we will do everything we can to support (them),害羞草研究所� Prime Minister Justin Trudeau told reporters on his way into question period.

Officials said the group was carrying out a normal nighttime training event for first officer pilots, and there were two pilots and two aircrew members on board at the time of the crash.

There was a recording device on the helicopter, but it is not clear whether it has been recovered from the wreckage.

The military is now conducting environmental containment and cleanup efforts on the river near the crash site and boaters are being asked to stay off the water. People in the area are also being asked to stay away from the beaches and shore until the work is complete.

Former Royal Canadian Air Force commander Andr茅 Deschamps said the fact that the crash happened on water complicates the efforts of investigators.

害羞草研究所淭he Ottawa River is a pretty fast-moving river, so it害羞草研究所檚 always difficult to deal with submerged platforms,害羞草研究所� he said in an interview Tuesday.

The retired lieutenant-general said the investigation would have started 害羞草研究所渁lmost on a parallel track害羞草研究所� to the rescue and recovery mission.

Chinook helicopters are intended for transporting personnel and equipment, and have been used in response to natural disasters and emergencies across the country.

Canada害羞草研究所檚 CH-147F version has been modified specifically for long-haul flights with a larger fuel capacity, Deschamps said.

The military is not speculating on what may have caused the crash while the investigation is underway.

Last August, the United States Air Force temporarily grounded its fleet of around 400 Chinooks after fuel leaks caused a small number of engine fires.

At the time, the Department of National Defence said there had been no such issues with its fleet but it was checking with the manufacturer, Boeing, and the U.S. military to see if any repairs or upgrades were needed.

害羞草研究所淟ike any global fleet, if there害羞草研究所檚 an issue of concern, the knowledge is shared amongst the users so everybody can make assessments on whether or not their fleet specifically requires attention,害羞草研究所� Deschamps said.

A spokesperson for Boeing declined to answer questions Tuesday about whether there had been reported issues with the Canadian fleet, referring all comment to the military. The Department of National Defence has not responded to questions.

For now, the fleet of 15 Chinooks based in Petawawa will not be flying.

害羞草研究所淭here is no formal pause in the operation of the fleet at this time. However, the fleet will take a pause out of respect for this tragic incident and all of the members of 450 Squadron,害羞草研究所� Anand said.

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