Do half orc savage attacks crits and barbarian brutal critical hits with a greatsword use both d6?

@JeremyECrawford do half orc savage attacks crits and barbarian brutal critical hits with a greatsword use both d6 again or just one?

— Derrick (@Scyllan8) June 6, 2016

Savage Attacks and Brutal Critical both let you roll one extra die. #DnD https://t.co/Vu0pQaIwH9

— Jeremy Crawford (@JeremyECrawford) June 11, 2016