Suppose Biden is undergoing the Presidential Inauguration and some emergency event (Fire alarm, alert to potential disruptive crowds/hostiles) makes the President incapable of performing the formalities and complete his oath, who would be the de-facto president then?
At Noon, the Previous President(Trump) would already be out of his office and Biden is not exactly "Incapacitated" which would have allowed for
Section 3 of the 20th Amendment:
"Section 3. If, at the time fixed for the beginning of the term of the President, the President elect shall have died, the Vice President elect shall become President.
Which would yield VP to gain power. But Biden won't be 'dead', merely incapicated. This seems confusing - Trump would officially have resigned but Biden wouldn't have been officially been made President. Would Kamala Harris be then the Temporary President?
What happens in this case? Who would hold the power? What are the legal provisions to prevent misuse of power by the Previous President (Trump) during this time, or his aides?
Edit: There was a simple misunderstanding - I meant that the emergency happened before the Inaugaration posing problems regarding the formalities involved and deciding who would the President in power.