When she heard the stunning news that rebels had brought an end to Syria's decades-old regime, Hayat al-Turki headed for a prison that had become known as a slaughterhouse, praying that her brother and five more relatives held there were still alive.

ABC News Chief Foreign Correspondent James Longman reports at Saydnaya prison, where Syrians are searching for their lost loved ones.

NBC News' Richard Engel reports from inside one of Syria's most notorious prisons, Saydnaya military prison nicknamed "the human slaughterhouse." Thousands of people in Syria have rushed to the country's prisons after the fall of the Assad regime searching for any trace of loved ones they feared had disappeared into their unseen depths.