Sounds like an engine failure. It happens. Procedures appeared to have been followed. Investigation to follow as to cause. Calling it a fire was premature - I think Journalist wanted a headline.
New engines fail. Old engines fail.
A small aircraft like the Saab has many landing options unlike the A380.
The engines for the Saab340 are propellor variants of the same turbine engines that drive military applications like the Apache and Black Hawks
The difference between turboprops and turbojets (that power the jets like the 737/380) is that turboprop exhausts do not have significant thrust unlike the turbojets. Other than that they are all variants of the turbine engine. There are no pistons despite what a commentator said on radio tonight.
And... the age of the airframe does not necessarily equate to the age of the engine.
What is Sandilands going to say this time. Last time he said the missing propellor Saab should have landed earlier in places including without emergency services rather than SYD.