Sickening CCTV shows the moment a young thug king hits a grandfather who asked him to turn his music down CCTV captures the moment Bon Williams, 20, brutally punches a 68-year-old man - leaving him with bleeding on the brain and several lost teeth - after he asked the attacker to turn his music down on a bus. Courtesy Channe7. SICKENING footage has emerged of a horrific one-punch attack on a grandfather who told a young man to turn his music down. The victim, 68, told off Bon Williams, 20, as they travelled on a bus in Dandenong North in March. When they got off, Williams put down his cans of Wild Turkey bourbon and punched the victim, who fell to the footpath and smashed his head on the concrete. Sisters Jessica Hosking, 17, and Breanna, 16, saw the attack unfold from the bus and made the driver stop so they could go to the victim's aid. Williams" victim collapses to the ground after the unexpected attack. Picture: Seven News. "It was such a low act," Jessica told the Herald Sun. My first thoughts were to save him and try and help him. She said his pulse stopped and she started CPR until paramedics arrived. "My nursing training and first aid training just kicked in," Jessica said. The victim suffered bleeding on his brain, a broken nose and lost several teeth. But Williams dodged jail and instead received a community corrections order. He later told Dandenong Magistrates" Court: "I'm remorseful and very sorry ... for being violent and aggressive." Dandenong High School students and sisters Breanna, 16, and Jessica, 17, stepped in to save the elderly man. Picture: Derrick den Hollander Source: News Corp Australia Strict coward punch sentences came into force on Saturday but Police Association secretary Ron Iddles said community attitudes to violence on our streets still needed to change. "I don't think younger people realise the damage one punch can do," he said. Young people don't realise life is so fragile. He said 40 per cent of serious assaults on Friday and Saturday nights were alcohol-fuelled. Your muscles are relaxed when drinking, you don't brace yourself ... You hit the road and it's all over," Sen-Sgt Iddles said. From Saturday, punching someone in the head without warning and killing them now carries a mandatory 10-year jail term. Manslaughter law has also been clarified to ensure offenders who punch their victims are appropriately punished. Attorney-General Robert Clark said: "Would-be offenders are now on notice. It's time to think again. Sen-Sgt Iddles said the legal changes would make it easier to convict one punch attackers. "From my previous experience in homicide, with one punch, it was difficult to prove they had an appreciation they were going to cause real serious injuries," he said. Twitter: @tminear