Sovetskaya Litva found itself free at the same time as the fall of Supreme Soviet of the Lithuanian SSR, what change allowed both of the actions to happen?
Supreme Soviet of the Lithuanian SSR The Supreme Soviet of the Lithuanian SSR (Lithuanian: "Lietuvos TSR Aukščiausioji Taryba" ; Russian: Верховный Совет Литовской ССР , "Verkhovnyy Sovet Litovskoy SSR") was the supreme soviet (main legislative institution) of the Lithuanian SSR, one of the republics comprising the Soviet Union. The Supreme Soviet was established in August 1940 when the People's Seimas declared itself the provisional Supreme Soviet. According to the constitution it was very similar to modern democratic parliaments: it was elected every four (later five) years and had the power to create, amend and ratify the constitution, laws, and treaties and appoint officials in the Council of Ministers (the executive branch). However, in reality the elections were staged, the Soviet had very little actual power and carried out orders given by the Communist Party of Lithuania (CPL). The situation changed in 1988, when the Lithuanians began seeking independence from the Soviet Union. The political power shifted from CPL to the Soviet, which adopted a number of important constitutional amendments and laws, paving the way for the independence. The first free elections were held in February 1990 and were won by pro-independence Sąjūdis. During its first session the Supreme Soviet adopted the Act of the Re-Establishment of the State of Lithuania and renamed itself the Supreme Council of the Republic of Lithuania.
Supreme Soviet of the Soviet Union The Supreme Soviet of the Soviet Union (Russian: Верхо́вный Сове́т СССР , "Verkhóvnyj Sovét SSSR") was the highest legislative body in the Soviet Union and the only one with the power to pass constitutional amendments. It elected the Presidium serving as the collective head of state of the Soviet Union, formed the Council of Ministers and the Supreme Court, and appointed the Procurator General of the Soviet Union.