Q:

A word that means an undeniable statement, stated emphatically

I'm looking for a word that means an emphatic, definitely correct, powerful assertion, kind of like "undeniable" except that doesn't capture the action aspect of making a statement. (A thesaurus didn't help). 
Things that almost work and why:

Proclamation - it gets the loud announcement aspect but misses the factual and undeniable aspects. One can make an incorrect proclamation.
Axiom - An axiom is certainly accurate and provable but axiom gives no indication of the method of delivery.
Apodictic - it gets the clearly established and beyond dispute but again misses the emphatic delivery aspect

Contextual examples:

to describe the act of yelling "the building is on fire" to twenty people who are standing nearby and somehow haven't noticed fifteen-meter flames coming out the windows. "Bob was kind enough to make the _____ that the building was on fire."
When someone has a banana in their ear and they can't hear you say "you have a banana in your ear!" you've stated a _____.

In response to close vote as discussed in comments below: "..undeniability (stating the obvious) is only a part of the idea to be conveyed. In my example of the fire, no one knew the building was burning so though it was obvious, no one noticed. The question you link to [as duplicate] requests something that describes telling a fact everyone already knows.."

A:

You're looking for "axiom", a statement that is regarded as being established, accepted, or self-evidently true.

axiom (noun) A self-evident or universally recognized truth; a maxim "It is an economic axiom as old as the hills that goods and services can be paid for only with goods and services" (Albert Jay Nock). TFD

axiomatic (adj)  relating to or resembling an axiom; self-evident

A:

Indubitable may work for you. A statement that is indisputable, and beyond any doubt. 

A:

Incontrovertible maybe?, like it can't be proven wrong.

