Green and black backpack lost on Dun Laoghaire East Pier

We lost a backpack on the Dun Laoghaire East Pier today. We took it off and forgot to put it back on when continuing the walk. We looked for it up and down the pier but could not find it anymore. It is a very distinctive backpack, black and green and with a green heart with the word "Steiermark" in it. It contains children's clothes, a portable phone and a wallet.