Why do the speaker of the house of representatives and the president pro tempore of the senate succeed to the presidency before the presidents secretary of state

The Constitution provides for a president pro tempore to preside over the Senate in the absence of the vice president. ... Following passage of the Presidential Succession Act of 1792, the president pro tempore was next in line after the vice president, and followed by the speaker of the House of Representatives.

Explanation:

the berlin blockade was an international crisis that arose from an attempt by the soviet union, in 1948–49, to force the western allied powers (the united states, the united kingdom, and france) to abandon their post-world war ii jurisdictions in west berlin. in march 1948 the allied powers decided to unite their different occupation zones of germany into a single economic unit. in protest, the soviet representative withdrew from the allied control council. coincident with the introduction of a new deutsche mark in west berlin (as throughout west germany), which the soviets regarded as a violation of agreements with the allies, the soviet occupation forces in eastern germany began a blockade of all rail, road, and water communications between berlin and the west. on june 24 the soviets announced that the four-power administration of berlin had ceased and that the allies no longer had any rights there.