HMS Amphion was first British warship sunk in World War One
6 August 2014 Last updated at 20:22 BST
She was the pride of Pembroke Dock but her crew became the first Royal Navy casualties of World War One.
Exactly 100 years ago, HMS Amphion hit a German mine and sank with the loss of 151 lives.
Sailors from Pembrokeshire were among those who died.
She was the first British warship destroyed in the conflict and, as Carwyn Jones reports, her loss sent shockwaves through the country.