A deadly fire at Canadian Forces Base Wainwright in Alberta has raised questions about military safety oversight after a federal audit warned five years earlier of serious deficiencies in fire prevention, hazard monitoring and enforcement.The fire-related training incident Saturday left four people dead and 39 others injured, bringing the total number of casualties to 43.Prime Minister Mark Carney said the Canadian Armed Forces has launched a comprehensive investigation into the tragedy and defended the military's ability to investigate itself.“Look, the military wants to get to the bottom of exactly what happened,” Carney told reporters. “They have started a comprehensive investigation. They have to rule out various things.”Asked whether he was comfortable allowing the military to investigate its own operations, Carney replied: “Absolutely.”“They’re aided by all the resources,” he said. “We will give them all the resources they need. They’re supported as well by the RCMP.”Blacklock's Reporter said Carney promised the investigation would determine what caused the deadly incident.“We will get the answers to what caused this terrible tragedy as expeditiously and transparently as possible,” he said.The prime minister did not provide further details about the investigation.A scheduled appearance by Army Commander Lt.-Gen. Michael Wright before the House of Commons defence committee was cancelled Monday, along with all other parliamentary proceedings.The tragedy comes five years after federal auditors identified widespread weaknesses in military safety programs, including failures to properly address fire hazards and enforce corrective measures..The 2021 Joint Audit And Evaluation Of The Department Of National Defence And Canadian Armed Forces Safety Program concluded the military needed to strengthen its oversight of workplace hazards.“Improvements are required,” auditors wrote.The report warned that dangerous conditions could be tolerated without proper authorization or adequate awareness among senior military officials.“There is a possibility hazards may be accepted at a level without the appropriate authority and limited senior management awareness of safety risks,” the audit stated.Auditors also warned the Department of National Defence and Canadian Armed Forces could face legal liability if they could not demonstrate that dangerous conditions were being properly inspected, assessed and corrected.Federal inspectors documented several potentially dangerous incidents, including a chemical tank with manually controlled temperatures that was mistakenly heated almost to its flash point.Inspectors also discovered water leaking above an electrical circuit board.The audit identified problems with tracking maintenance orders and ensuring repairs were completed after hazards were discovered.“There are also issues with the ability to track work orders to make required repairs and maintenance to mitigate hazards as noted by the chief fire inspectors,” the report stated.Military fire inspectors were also found to lack the authority needed to ensure urgent safety problems were corrected promptly.“Chief Fire Inspectors noted that while they perform follow-ups regarding corrective action, they do not have authority to expedite corrective measures,” auditors wrote.The report concluded that safety procedures were not being consistently followed and that monitoring systems were inadequate.“Oversight mechanisms do not adequately ensure that all required procedures are being followed,” the audit said..Auditors warned that the consequences of inadequate safety programs extended beyond workplace injuries and could undermine military operations.“Hazardous occurrences are impediments to defence capability, readiness and mission success,” the report stated.The audit emphasized that military personnel routinely operate in hazardous environments, making effective safety procedures particularly important.It also warned that failures to address identified deficiencies could expose the federal government to lawsuits and financial consequences.“The Department of National Defence and Canadian Armed Forces may be exposed to operational, reputational, litigation and financial risks should the safety program not deliver on its intended objectives,” auditors concluded.The cause of Saturday's fire remains under investigation. No determination has been reported linking the Wainwright tragedy to the deficiencies identified in the 2021 audit.