Cossu died after a building fell on him in the village of Pescara del Tronto, where he was vacationing, the Telegraph reported. He was 45 years old. Thankfully, Flash isn't alone and has Cossu's wife to continue watching over him.
Flash's heartbreaking show of dedication proves that dogs really are man's best friend - even up until the very end.
See how you can contribute to Italy's ongoing rescue and recovery efforts here.
Watch a video of Flash remaining by his owner's side during the funeral below: