No- this has not happened yet.
the vice president
The VP becomes president whenever the president dies or resigns. If the president is temporarily unable to discharge his duties, the VP can temporarily be authorized to act as president.
if there is no president or vice president, i think the chairman of the house of representatives serves temporarily
the vice president takes over until further notice
Yes. There are provisions in the 25th amendment whereby the powers of the President can temporarily be assigned to the vice-president.
The vice-president becomes president if the presidency is vacated.
If the President dies (or is permanently incapacitated), the Vice President succeeds to the Presidency for the remainder of the President's term. If there is sufficient time involved, a new Vice President will be nominated to serve the Vice President's term. If the President is alive but temporarily incapacitated, there is a complicated procedure for allowing the Vice President to act as Acting President temporarily, as spelled out in the 25th Amendment to the US Constitution. The amendment considers the cases where the President voluntarily yields his powers or when he does not, as well as the process of returning the powers to the President if he recovers.
vice president, & if he dies, the speaker of the house
In this case the vice president would assume the duties of the president temporarily.
The Vice President of the United States has only two designated functions. He (or she) presides over sessions of the US Senate. And he (or she) becomes president or fills in temporarily if the President is killed or incapacitated. Beyond that, the Vice President does whatever the President wants, as long as it is legal.
While all is well with the President, the Vice President's primary job as President of the Senate makes him part of the legislative branch. If anything happens to the President requiring the Vice President to step in to take his/her place, whether temporarily or permanently, he becomes part of the executive branch.
The vice president becomes President if the President dies or is removed from office . There are also procedures by which the vice-president can temporarily assume the duties of president, either voluntarily or involuntarily.