Search underway for Australian surfer likely killed in shark attack / Missing Australian surfer likely killed by shark: Police / Tributes for Kiwi surfer missing off Western Australia beach, search called off indefinitely / Details emerge about alleged killer of Australian and U.S. surfers / Mother of Australian surfers killed in Mexico delivers touching eulogy at San Diego beach / Mother of Australian surfers killed in Mexico delivers moving tribute: 'World has become a darker place' / Mother of Australian surfers killed in Mexico gives moving tribute to sons at a beach in San Diego / Australian PM mourns 'tragic' deaths of surfers killed in Mexico