The most famous case of a Vestal being punished in this manner is that of the Chief Vestal Cornelia during the reign of Domitian. This is what Suetonius says about it:

Taking a far more serious view than his father and brother had done of unchastity among the Vestals, [Domitian] began by sentencing offenders to execution, and afterwards resorted to the traditional form of punishment. Thus, though he allowed the Occulata sisters, and Varonilla, to chose how they should die, and sent their lovers into exile, he later ordered Cornelia, a Chief Vestal - acquitted at her first trial, but rearrested much later and convicted - to be buried alive and had her 'lovers' clubbed to death in the Comitium.

The first three mentioned above were put to death in 83 AD and Cornelia met her end 7 years later.

After the Battle of Cannae in 216 BC, it was decided it was not the fault of the generals. Oh no, it had to be the Vestals so two were condemned and put to death.

In 114 BC, the Pontiffs condemned another Vestal to death and then the next year, on the motion of the tribune who accused the Pontiffs of partiality, two of the Vestals who were acquitted the year before were found guilty and put to death.

These are the only records I found of actual condemnations. There are other stories of women who were accused but acquitted such as Fabia who was the half sister of Cicero's wife, Terentia.

I do apologize for posting even though I'm not a member....er...demis have a talent for that. Its a subject that I love.