This is VERY BIG NEWS in Canada today.
... and the sub wasn't that old. The CAF had just purchased it from the RN, and it was built in either the late eighties or early nineties.
They'd made 140 km from picking it up from the RN when the fire broke out.
The RN is trying to say it was the Canadian sailors' fault. I imagine this is because they don't want to be on the hook for the repair bill.