
A Vestal who broke her vow of chastity was buried alive, as happened to Cornelia, a Chief Vestal (vestalis maxima) condemned to death by Domitian in AD 90. The statue of a Chief Vestal pictured above was found in the House of the Vestals.
Reference: The illustration is from What Life Was Like: When Rome Ruled the World: The Roman Empire, 100 BC-AD 200 (1997) by the Editors of Time-Life Books.