House Point's Hourglass Shatter

Apparently, when a Hogwarts House suffers a great loss, the hourglass that that specific person belonged to shatters. Albus Dumbledore died in Harry Potter and the Half-Blood Prince, the Gryffindor hourglass was shattered. However, when Lord Voldemort was defeated in Harry Potter and the Deathly Hallows, it was the Slytherin hourglass that was shattered.

However, it is also possible that this it only happens when a Witch or Wizard dies within the grounds of Hogwarts. (Albus Dumbledore died on the Astronomy Tower, and Lord Voldemort died in the Great Hall)

Appearances

 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Deathly Hallows