Does speaker of the house rise to presidency?

Answer 1

He (or she) is next in line after the VP.

This is how Gerald Ford became president-- the President and VP both resigned.

The above is a little misleading. The VP resigned and in accordance with the constitution, the president nominated Ford to be VP. He could have nominated anybody, but he knew that Ford was a popular member of the House and was likely to be confirmed. At this time nobody expected Nixon to resign.

The above answer pertains to the extraordinary event where the president and vice-president both leave office or die at the same time, perhaps because of an enemy attack or terrorist plot and before a new VP can be put in place.