Fire on board?

Another theory is the possible of a fire could have happened on board. So could a potential fire have taken down MH370. If I look closely at this the fire had to erupt really quick. In order for the fire to occur a spark had to happen in the main electric line above the cockpit. So the chances that could have happened is the A/C had started an electric fire. But there is some evidence that shows there were some batteries that can catch on fire. The problem I have here is let's say the fire happen in the cargo part of the plane there should have been alarm alerting a fire is on board. Due to technology advancements, we have today.

So how could the fire impact the communication to the ground and why was there no alert ping to the ground? Sadly with no black boxes we will never know.
Resources
Zurcher, Anthony. "An MH370 Theory That Was Simple, Compelling and Wrong." BBC News. Echo Chambers, 19 Mar. 2014. Web. 09 May 2016.
This article talked about how the possible of fire could have been possible but had made little to no sense on it. This evidence also shows that pilot had many flight hours and should have know what to do in those situation. This also shows the possible outbreaks of fire could have happen on the airplane.